diff --git a/client/src/App.tsx b/client/src/App.tsx
index 5e0f5ed2..f5d96b51 100644
--- a/client/src/App.tsx
+++ b/client/src/App.tsx
@@ -58,7 +58,7 @@ function ProtectedRoute({ children, adminRequired = false, addonId }: ProtectedR
   }
 
   if (!isAuthenticated) {
-    const redirectParam = encodeURIComponent(location.pathname + location.search)
+    const redirectParam = encodeURIComponent(location.pathname + location.search + location.hash)
     return <Navigate to={`/login?redirect=${redirectParam}`} replace />
   }
 
diff --git a/client/src/api/client.ts b/client/src/api/client.ts
index 378ddeab..e39c6a47 100644
--- a/client/src/api/client.ts
+++ b/client/src/api/client.ts
@@ -75,7 +75,7 @@ apiClient.interceptors.response.use(
     if (error.response?.status === 401 && (error.response?.data as { code?: string } | undefined)?.code === 'AUTH_REQUIRED') {
       const { pathname } = window.location
       if (!isAuthPublicPath(pathname)) {
-        const currentPath = pathname + window.location.search
+        const currentPath = pathname + window.location.search + window.location.hash
         window.location.href = '/login?redirect=' + encodeURIComponent(currentPath)
       }
     }
diff --git a/client/src/components/Planner/DayDetailPanel.test.tsx b/client/src/components/Planner/DayDetailPanel.test.tsx
index 279fa46b..9bdc0256 100644
--- a/client/src/components/Planner/DayDetailPanel.test.tsx
+++ b/client/src/components/Planner/DayDetailPanel.test.tsx
@@ -892,6 +892,183 @@ describe('DayDetailPanel', () => {
     expect(screen.getByText(/June|15/i)).toBeInTheDocument();
   });
 
+  // ── Accommodation date-range picker — non-monotonic day IDs (issue #889) ─────
+
+  // Builds the reporter's exact ID layout: day_number 1-9 → IDs 17-25, day_number 10-16 → IDs 1-7.
+  // This happens after repeated trip-length changes via generateDays (no import/migration needed).
+  function buildNonMonotonicDays() {
+    return [
+      buildDay({ id: 17, trip_id: 1, date: '2026-04-30' }),
+      buildDay({ id: 18, trip_id: 1, date: '2026-05-01' }),
+      buildDay({ id: 19, trip_id: 1, date: '2026-05-02' }),
+      buildDay({ id: 20, trip_id: 1, date: '2026-05-03' }),
+      buildDay({ id: 21, trip_id: 1, date: '2026-05-04' }),
+      buildDay({ id: 22, trip_id: 1, date: '2026-05-05' }),
+      buildDay({ id: 23, trip_id: 1, date: '2026-05-06' }),
+      buildDay({ id: 24, trip_id: 1, date: '2026-05-07' }),
+      buildDay({ id: 25, trip_id: 1, date: '2026-05-08' }),
+      buildDay({ id: 1,  trip_id: 1, date: '2026-05-09' }),
+      buildDay({ id: 2,  trip_id: 1, date: '2026-05-10' }),
+      buildDay({ id: 3,  trip_id: 1, date: '2026-05-11' }),
+      buildDay({ id: 4,  trip_id: 1, date: '2026-05-12' }),
+      buildDay({ id: 5,  trip_id: 1, date: '2026-05-13' }),
+      buildDay({ id: 6,  trip_id: 1, date: '2026-05-14' }),
+      buildDay({ id: 7,  trip_id: 1, date: '2026-05-15' }),
+    ];
+  }
+
+  // Returns the two CustomSelect trigger buttons for start/end day pickers.
+  // When no dropdown is open, these are the only globally-visible buttons whose textContent
+  // matches /Day \d+/ (the main panel title is a div, not a button).
+  // [0] = start trigger, [1] = end trigger (DOM source order).
+  function getDayPickerTriggers() {
+    return screen.getAllByRole('button').filter(b => /Day \d+/.test(b.textContent ?? ''));
+  }
+
+  it('FE-PLANNER-DAYDETAIL-056: non-monotonic IDs — end picker does not clobber start-day', async () => {
+    const days = buildNonMonotonicDays();
+    const place = buildPlace({ id: 50, name: 'Range Hotel' });
+    let capturedBody: any;
+    server.use(
+      http.post('/api/trips/1/accommodations', async ({ request }) => {
+        capturedBody = await request.json();
+        return HttpResponse.json({
+          accommodation: {
+            id: 99, place_id: 50, place_name: 'Range Hotel', place_address: null,
+            start_day_id: capturedBody.start_day_id, end_day_id: capturedBody.end_day_id,
+            check_in: null, check_out: null, confirmation: null,
+          },
+        });
+      }),
+    );
+
+    render(<DayDetailPanel {...defaultProps} day={days[0]} days={days} places={[place]} />);
+    await userEvent.click(await screen.findByText(/Add accommodation/i));
+    await userEvent.click(await screen.findByRole('button', { name: /Range Hotel/i }));
+
+    // Both triggers show "Day 1"; the second one is the end picker.
+    await userEvent.click(getDayPickerTriggers()[1]);
+    // Select "Day 16" (id=7) from the open dropdown — textContent starts with "Day 16".
+    await userEvent.click(screen.getAllByRole('button').find(b => b.textContent?.startsWith('Day 16'))!);
+
+    await userEvent.click(screen.getByRole('button', { name: /^Save$/i }));
+
+    await waitFor(() => {
+      // start must remain id 17 (day 1) — old code would clobber it to id 7 via Math.min
+      expect(capturedBody?.start_day_id).toBe(17);
+      expect(capturedBody?.end_day_id).toBe(7);
+    });
+  });
+
+  it('FE-PLANNER-DAYDETAIL-057: non-monotonic IDs — start picker does not collapse end when start has high ID', async () => {
+    const days = buildNonMonotonicDays();
+    const place = buildPlace({ id: 51, name: 'Span Hotel' });
+    let capturedBody: any;
+    server.use(
+      http.post('/api/trips/1/accommodations', async ({ request }) => {
+        capturedBody = await request.json();
+        return HttpResponse.json({
+          accommodation: {
+            id: 100, place_id: 51, place_name: 'Span Hotel', place_address: null,
+            start_day_id: capturedBody.start_day_id, end_day_id: capturedBody.end_day_id,
+            check_in: null, check_out: null, confirmation: null,
+          },
+        });
+      }),
+    );
+
+    render(<DayDetailPanel {...defaultProps} day={days[0]} days={days} places={[place]} />);
+    await userEvent.click(await screen.findByText(/Add accommodation/i));
+    await userEvent.click(await screen.findByRole('button', { name: /Span Hotel/i }));
+
+    // Set end to day 16 (id=7, low ID but last day by position).
+    await userEvent.click(getDayPickerTriggers()[1]);
+    await userEvent.click(screen.getAllByRole('button').find(b => b.textContent?.startsWith('Day 16'))!);
+
+    // Set start to day 9 (id=25, high ID, but earlier by position than day 16).
+    // Old code: Math.max(25, 7) = 25 → end collapses to day 9.
+    // New code: position(id=25)=8 < position(id=7)=15 → end stays at 7 (day 16).
+    await userEvent.click(getDayPickerTriggers()[0]);
+    await userEvent.click(screen.getAllByRole('button').find(b => b.textContent?.startsWith('Day 9'))!);
+
+    await userEvent.click(screen.getByRole('button', { name: /^Save$/i }));
+
+    await waitFor(() => {
+      expect(capturedBody?.start_day_id).toBe(25); // day 9
+      expect(capturedBody?.end_day_id).toBe(7);    // day 16 — must NOT have collapsed
+    });
+  });
+
+  it('FE-PLANNER-DAYDETAIL-058: non-monotonic IDs — All days button sets correct first/last IDs', async () => {
+    const days = buildNonMonotonicDays();
+    const place = buildPlace({ id: 52, name: 'Full Trip Hotel' });
+    let capturedBody: any;
+    server.use(
+      http.post('/api/trips/1/accommodations', async ({ request }) => {
+        capturedBody = await request.json();
+        return HttpResponse.json({
+          accommodation: {
+            id: 101, place_id: 52, place_name: 'Full Trip Hotel', place_address: null,
+            start_day_id: capturedBody.start_day_id, end_day_id: capturedBody.end_day_id,
+            check_in: null, check_out: null, confirmation: null,
+          },
+        });
+      }),
+    );
+
+    render(<DayDetailPanel {...defaultProps} day={days[0]} days={days} places={[place]} />);
+    await userEvent.click(await screen.findByText(/Add accommodation/i));
+    await userEvent.click(await screen.findByRole('button', { name: /Full Trip Hotel/i }));
+
+    // "All" is the day.allDays translation (en: "All") — the Apply-to-entire-trip button.
+    // When categories=[] the category-filter "All" button is not rendered, so this is unique.
+    await userEvent.click(screen.getByRole('button', { name: /^All$/i }));
+    await userEvent.click(screen.getByRole('button', { name: /^Save$/i }));
+
+    await waitFor(() => {
+      // days[0].id=17 (first by position), days[15].id=7 (last by position)
+      expect(capturedBody?.start_day_id).toBe(17);
+      expect(capturedBody?.end_day_id).toBe(7);
+    });
+  });
+
+  it('FE-PLANNER-DAYDETAIL-059: sequential IDs — end picker clamping still works (regression guard)', async () => {
+    const seqDays = [
+      buildDay({ id: 101, trip_id: 1, date: '2026-06-01' }),
+      buildDay({ id: 102, trip_id: 1, date: '2026-06-02' }),
+      buildDay({ id: 103, trip_id: 1, date: '2026-06-03' }),
+    ];
+    const place = buildPlace({ id: 53, name: 'Seq Hotel' });
+    let capturedBody: any;
+    server.use(
+      http.post('/api/trips/1/accommodations', async ({ request }) => {
+        capturedBody = await request.json();
+        return HttpResponse.json({
+          accommodation: {
+            id: 102, place_id: 53, place_name: 'Seq Hotel', place_address: null,
+            start_day_id: capturedBody.start_day_id, end_day_id: capturedBody.end_day_id,
+            check_in: null, check_out: null, confirmation: null,
+          },
+        });
+      }),
+    );
+
+    render(<DayDetailPanel {...defaultProps} day={seqDays[0]} days={seqDays} places={[place]} />);
+    await userEvent.click(await screen.findByText(/Add accommodation/i));
+    await userEvent.click(await screen.findByRole('button', { name: /Seq Hotel/i }));
+
+    // Pick end = day 3 (id=103, position 2 > position 0 of start id=101).
+    await userEvent.click(getDayPickerTriggers()[1]);
+    await userEvent.click(screen.getAllByRole('button').find(b => b.textContent?.startsWith('Day 3'))!);
+
+    await userEvent.click(screen.getByRole('button', { name: /^Save$/i }));
+
+    await waitFor(() => {
+      expect(capturedBody?.start_day_id).toBe(101);
+      expect(capturedBody?.end_day_id).toBe(103);
+    });
+  });
+
   it('FE-PLANNER-DAYDETAIL-040: 12h time format renders reservation time with AM/PM', async () => {
     seedStore(useSettingsStore, {
       settings: { time_format: '12h', temperature_unit: 'celsius', blur_booking_codes: false },
diff --git a/client/src/components/Planner/DayDetailPanel.tsx b/client/src/components/Planner/DayDetailPanel.tsx
index 9487f402..0d53f8ff 100644
--- a/client/src/components/Planner/DayDetailPanel.tsx
+++ b/client/src/components/Planner/DayDetailPanel.tsx
@@ -463,7 +463,7 @@ export default function DayDetailPanel({ day, days, places, categories = [], tri
                       <div style={{ flex: 1, minWidth: 0 }}>
                         <CustomSelect
                           value={hotelDayRange.start}
-                          onChange={v => setHotelDayRange(prev => ({ start: v, end: Math.max(v, prev.end) }))}
+                          onChange={v => setHotelDayRange(prev => ({ start: v, end: days.findIndex(d => d.id === v) > days.findIndex(d => d.id === prev.end) ? v : prev.end }))}
                           options={days.map((d, i) => ({
                             value: d.id,
                             label: d.title || t('planner.dayN', { n: i + 1 }),
@@ -478,7 +478,7 @@ export default function DayDetailPanel({ day, days, places, categories = [], tri
                       <div style={{ flex: 1, minWidth: 0 }}>
                         <CustomSelect
                           value={hotelDayRange.end}
-                          onChange={v => setHotelDayRange(prev => ({ start: Math.min(prev.start, v), end: v }))}
+                          onChange={v => setHotelDayRange(prev => ({ start: days.findIndex(d => d.id === v) < days.findIndex(d => d.id === prev.start) ? v : prev.start, end: v }))}
                           options={days.map((d, i) => ({
                             value: d.id,
                             label: d.title || t('planner.dayN', { n: i + 1 }),
diff --git a/client/src/pages/LoginPage.oidc-redirect.test.tsx b/client/src/pages/LoginPage.oidc-redirect.test.tsx
new file mode 100644
index 00000000..c14e0d96
--- /dev/null
+++ b/client/src/pages/LoginPage.oidc-redirect.test.tsx
@@ -0,0 +1,105 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+import { render, screen, waitFor } from '../../tests/helpers/render';
+import { http, HttpResponse } from 'msw';
+import { server } from '../../tests/helpers/msw/server';
+import { resetAllStores } from '../../tests/helpers/store';
+import LoginPage from './LoginPage';
+
+const mockNavigate = vi.fn();
+vi.mock('react-router-dom', async () => {
+  const actual = await vi.importActual('react-router-dom');
+  return { ...actual, useNavigate: () => mockNavigate };
+});
+
+describe('LoginPage — OIDC redirect preservation', () => {
+  let savedLocation: Location;
+
+  beforeEach(() => {
+    resetAllStores();
+    mockNavigate.mockClear();
+    sessionStorage.clear();
+    savedLocation = window.location;
+  });
+
+  afterEach(() => {
+    Object.defineProperty(window, 'location', {
+      configurable: true,
+      writable: true,
+      value: savedLocation,
+    });
+  });
+
+  function setSearch(search: string) {
+    Object.defineProperty(window, 'location', {
+      configurable: true,
+      writable: true,
+      value: { ...window.location, search },
+    });
+  }
+
+  describe('FE-PAGE-LOGIN-022: redirect param stashed in sessionStorage on mount', () => {
+    it('saves decoded redirect to sessionStorage when ?redirect= is present', async () => {
+      setSearch('?redirect=%2Foauth%2Fauthorize%3Fclient_id%3Dfoo');
+      render(<LoginPage />);
+
+      await waitFor(() => {
+        expect(sessionStorage.getItem('oidc_redirect')).toBe('/oauth/authorize?client_id=foo');
+      });
+    });
+
+    it('does not write to sessionStorage when no redirect param is present', async () => {
+      render(<LoginPage />);
+      await waitFor(() => {
+        expect(screen.getByPlaceholderText('your@email.com')).toBeInTheDocument();
+      });
+
+      expect(sessionStorage.getItem('oidc_redirect')).toBeNull();
+    });
+  });
+
+  describe('FE-PAGE-LOGIN-023: OIDC code exchange navigates to sessionStorage redirect', () => {
+    beforeEach(() => {
+      server.use(
+        http.get('/api/auth/oidc/exchange', () =>
+          HttpResponse.json({ token: 'mock-oidc-token' })
+        ),
+      );
+    });
+
+    it('navigates to the saved sessionStorage redirect after successful OIDC exchange', async () => {
+      sessionStorage.setItem('oidc_redirect', '/oauth/authorize?client_id=foo&state=xyz');
+      setSearch('?oidc_code=testcode123');
+      render(<LoginPage />);
+
+      await waitFor(() => {
+        expect(mockNavigate).toHaveBeenCalledWith(
+          '/oauth/authorize?client_id=foo&state=xyz',
+          { replace: true },
+        );
+      });
+
+      expect(sessionStorage.getItem('oidc_redirect')).toBeNull();
+    });
+
+    it('falls back to /dashboard when no sessionStorage redirect is set', async () => {
+      setSearch('?oidc_code=testcode123');
+      render(<LoginPage />);
+
+      await waitFor(() => {
+        expect(mockNavigate).toHaveBeenCalledWith('/dashboard', { replace: true });
+      });
+    });
+  });
+
+  describe('FE-PAGE-LOGIN-024: OIDC error clears sessionStorage redirect', () => {
+    it('removes oidc_redirect from sessionStorage on OIDC error', async () => {
+      sessionStorage.setItem('oidc_redirect', '/oauth/authorize?client_id=foo');
+      setSearch('?oidc_error=token_failed');
+      render(<LoginPage />);
+
+      await waitFor(() => {
+        expect(sessionStorage.getItem('oidc_redirect')).toBeNull();
+      });
+    });
+  });
+});
diff --git a/client/src/pages/LoginPage.tsx b/client/src/pages/LoginPage.tsx
index d4646635..6fa2c192 100644
--- a/client/src/pages/LoginPage.tsx
+++ b/client/src/pages/LoginPage.tsx
@@ -55,6 +55,12 @@ export default function LoginPage(): React.ReactElement {
     return '/dashboard'
   }, [])
 
+  useEffect(() => {
+    if (redirectTarget !== '/dashboard') {
+      sessionStorage.setItem('oidc_redirect', redirectTarget)
+    }
+  }, [redirectTarget])
+
   useEffect(() => {
     const params = new URLSearchParams(window.location.search)
 
@@ -83,7 +89,9 @@ export default function LoginPage(): React.ReactElement {
           window.history.replaceState({}, '', '/login')
           if (data.token) {
             await loadUser()
-            navigate('/dashboard', { replace: true })
+            const savedRedirect = sessionStorage.getItem('oidc_redirect') || '/dashboard'
+            sessionStorage.removeItem('oidc_redirect')
+            navigate(savedRedirect, { replace: true })
           } else {
             setError(data.error || t('login.oidcFailed'))
           }
@@ -104,6 +112,7 @@ export default function LoginPage(): React.ReactElement {
         invalid_state: t('login.oidc.invalidState'),
       }
       setError(errorMessages[oidcError] || oidcError)
+      sessionStorage.removeItem('oidc_redirect')
       window.history.replaceState({}, '', '/login')
       return
     }
diff --git a/client/src/pages/OAuthAuthorizePage.tsx b/client/src/pages/OAuthAuthorizePage.tsx
index 457d96ae..681326f2 100644
--- a/client/src/pages/OAuthAuthorizePage.tsx
+++ b/client/src/pages/OAuthAuthorizePage.tsx
@@ -124,7 +124,7 @@ export default function OAuthAuthorizePage(): React.ReactElement {
   }
 
   function handleLoginRedirect() {
-    const next = '/oauth/authorize?' + params.toString()
+    const next = '/oauth/authorize?' + params.toString() + window.location.hash
     window.location.href = '/login?redirect=' + encodeURIComponent(next)
   }
 
diff --git a/server/src/app.ts b/server/src/app.ts
index d21c0d3c..cc83b645 100644
--- a/server/src/app.ts
+++ b/server/src/app.ts
@@ -53,7 +53,7 @@ export function createApp(): express.Application {
   const app = express();
 
   // Trust first proxy (nginx/Docker) for correct req.ip
-  if (process.env.NODE_ENV === 'production' || process.env.TRUST_PROXY) {
+  if (process.env.NODE_ENV?.toLowerCase() === 'production' || process.env.TRUST_PROXY) {
     app.set('trust proxy', Number.parseInt(process.env.TRUST_PROXY) || 1);
   }
 
@@ -67,13 +67,13 @@ export function createApp(): express.Application {
       if (!origin || allowedOrigins.includes(origin)) callback(null, true);
       else callback(new Error('Not allowed by CORS'));
     };
-  } else if (process.env.NODE_ENV === 'production') {
+  } else if (process.env.NODE_ENV?.toLowerCase() === 'production') {
     corsOrigin = false;
   } else {
     corsOrigin = true;
   }
 
-  const shouldForceHttps = process.env.FORCE_HTTPS === 'true';
+  const shouldForceHttps = process.env.FORCE_HTTPS?.toLowerCase() === 'true';
   // HSTS is worth enabling any time we're serving production traffic,
   // not only when FORCE_HTTPS is set. Self-hosters behind Traefik /
   // Caddy / Cloudflare Tunnel typically leave FORCE_HTTPS unset (the
diff --git a/server/src/config.ts b/server/src/config.ts
index 2941a87f..c9255cc9 100644
--- a/server/src/config.ts
+++ b/server/src/config.ts
@@ -105,7 +105,7 @@ export const ENCRYPTION_KEY = _encryptionKey;
 // Must stay in sync with client/src/i18n/supportedLanguages.ts (canonical source).
 // Kept duplicated here because server and client are separate npm packages.
 const SUPPORTED_LANG_CODES = ['de', 'en', 'es', 'fr', 'hu', 'nl', 'br', 'cs', 'pl', 'ru', 'zh', 'zh-TW', 'it', 'ar'];
-const rawDefaultLang = process.env.DEFAULT_LANGUAGE || 'en';
+const rawDefaultLang = process.env.DEFAULT_LANGUAGE?.toLowerCase() || 'en';
 if (!SUPPORTED_LANG_CODES.includes(rawDefaultLang)) {
   console.warn(`DEFAULT_LANGUAGE="${rawDefaultLang}" is not supported. Falling back to "en". Supported: ${SUPPORTED_LANG_CODES.join(', ')}`);
 }
diff --git a/server/src/db/database.ts b/server/src/db/database.ts
index 2578608b..e7057fd4 100644
--- a/server/src/db/database.ts
+++ b/server/src/db/database.ts
@@ -47,7 +47,7 @@ const db = new Proxy({} as Database.Database, {
   },
 });
 
-if (process.env.DEMO_MODE === 'true') {
+if (process.env.DEMO_MODE?.toLowerCase() === 'true') {
   try {
     const { seedDemoData } = require('../demo/demo-seed');
     seedDemoData(_db);
diff --git a/server/src/db/seeds.ts b/server/src/db/seeds.ts
index d6e01d54..299e3f5a 100644
--- a/server/src/db/seeds.ts
+++ b/server/src/db/seeds.ts
@@ -6,7 +6,7 @@ import crypto from 'crypto';
 // are only relevant after the first user exists; at that point seeds have already
 // finished and skip via the userCount > 0 guard above.
 function isOidcOnlyConfigured(): boolean {
-  if (process.env.OIDC_ONLY !== 'true') return false;
+  if (process.env.OIDC_ONLY?.toLowerCase() !== 'true') return false;
   return !!(process.env.OIDC_ISSUER && process.env.OIDC_CLIENT_ID);
 }
 
diff --git a/server/src/index.ts b/server/src/index.ts
index 3f1bf8dd..0e699f37 100644
--- a/server/src/index.ts
+++ b/server/src/index.ts
@@ -29,8 +29,9 @@ const server = app.listen(PORT, () => {
   const banner = [
     '──────────────────────────────────────',
     '  TREK API started',
+    `  Version      ${process.env.APP_VERSION}`,
     `  Port:        ${PORT}`,
-    `  Environment: ${process.env.NODE_ENV || 'development'}`,
+    `  Environment: ${process.env.NODE_ENV?.toLowerCase() || 'development'}`,
     `  Timezone:    ${tz}`,
     `  Origins:     ${origins}`,
     `  Log level:   ${LOG_LVL}`,
@@ -40,8 +41,8 @@ const server = app.listen(PORT, () => {
     '──────────────────────────────────────',
   ];
   banner.forEach(l => console.log(l));
-  if (process.env.DEMO_MODE === 'true') sLogInfo('Demo mode: ENABLED');
-  if (process.env.DEMO_MODE === 'true' && process.env.NODE_ENV === 'production') {
+  if (process.env.DEMO_MODE?.toLowerCase() === 'true') sLogInfo('Demo mode: ENABLED');
+  if (process.env.DEMO_MODE?.toLowerCase() === 'true' && process.env.NODE_ENV?.toLowerCase() === 'production') {
     sLogWarn('SECURITY WARNING: DEMO_MODE is enabled in production!');
   }
   scheduler.start();
diff --git a/server/src/middleware/auth.ts b/server/src/middleware/auth.ts
index 9f254403..18be7236 100644
--- a/server/src/middleware/auth.ts
+++ b/server/src/middleware/auth.ts
@@ -105,7 +105,7 @@ const adminOnly = (req: Request, res: Response, next: NextFunction): void => {
 
 const demoUploadBlock = (req: Request, res: Response, next: NextFunction): void => {
   const authReq = req as AuthRequest;
-  if (process.env.DEMO_MODE === 'true' && isDemoEmail(authReq.user?.email)) {
+  if (process.env.DEMO_MODE?.toLowerCase() === 'true' && isDemoEmail(authReq.user?.email)) {
     res.status(403).json({ error: 'Uploads are disabled in demo mode. Self-host TREK for full functionality.' });
     return;
   }
diff --git a/server/src/middleware/mfaPolicy.ts b/server/src/middleware/mfaPolicy.ts
index b253acc0..70b00896 100644
--- a/server/src/middleware/mfaPolicy.ts
+++ b/server/src/middleware/mfaPolicy.ts
@@ -68,7 +68,7 @@ export function enforceGlobalMfaPolicy(req: Request, res: Response, next: NextFu
     return;
   }
 
-  if (process.env.DEMO_MODE === 'true' && verified.email && DEMO_EMAILS.has(verified.email)) {
+  if (process.env.DEMO_MODE?.toLowerCase() === 'true' && verified.email && DEMO_EMAILS.has(verified.email)) {
     next();
     return;
   }
diff --git a/server/src/routes/admin.ts b/server/src/routes/admin.ts
index 7cd32712..16a5b40b 100644
--- a/server/src/routes/admin.ts
+++ b/server/src/routes/admin.ts
@@ -449,7 +449,7 @@ router.put('/default-user-settings', (req: Request, res: Response) => {
 });
 
 // ── Dev-only: test notification endpoints ──────────────────────────────────────
-if (process.env.NODE_ENV === 'development') {
+if (process.env.NODE_ENV?.toLowerCase() === 'development') {
   const { send } = require('../services/notificationService');
 
   router.post('/dev/test-notification', async (req: Request, res: Response) => {
diff --git a/server/src/routes/backup.ts b/server/src/routes/backup.ts
index 2d9ce088..58e5995a 100644
--- a/server/src/routes/backup.ts
+++ b/server/src/routes/backup.ts
@@ -168,7 +168,7 @@ router.put('/auto-settings', (req: Request, res: Response) => {
     const msg = err instanceof Error ? err.message : String(err);
     res.status(500).json({
       error: 'Could not save auto-backup settings',
-      detail: process.env.NODE_ENV !== 'production' ? msg : undefined,
+      detail: process.env.NODE_ENV?.toLowerCase() !== 'production' ? msg : undefined,
     });
   }
 });
diff --git a/server/src/routes/oidc.ts b/server/src/routes/oidc.ts
index 4a86a340..7aefe593 100644
--- a/server/src/routes/oidc.ts
+++ b/server/src/routes/oidc.ts
@@ -30,7 +30,7 @@ router.get('/login', async (req: Request, res: Response) => {
   const config = getOidcConfig();
   if (!config) return res.status(400).json({ error: 'OIDC not configured' });
 
-  if (config.issuer && !config.issuer.startsWith('https://') && process.env.NODE_ENV === 'production') {
+  if (config.issuer && !config.issuer.startsWith('https://') && process.env.NODE_ENV?.toLowerCase() === 'production') {
     return res.status(400).json({ error: 'OIDC issuer must use HTTPS in production' });
   }
 
@@ -85,7 +85,7 @@ router.get('/callback', async (req: Request, res: Response) => {
   const config = getOidcConfig();
   if (!config) return res.redirect(frontendUrl('/login?oidc_error=not_configured'));
 
-  if (config.issuer && !config.issuer.startsWith('https://') && process.env.NODE_ENV === 'production') {
+  if (config.issuer && !config.issuer.startsWith('https://') && process.env.NODE_ENV?.toLowerCase() === 'production') {
     return res.redirect(frontendUrl('/login?oidc_error=issuer_not_https'));
   }
 
diff --git a/server/src/scheduler.ts b/server/src/scheduler.ts
index 87979ecc..13177b7f 100644
--- a/server/src/scheduler.ts
+++ b/server/src/scheduler.ts
@@ -139,7 +139,7 @@ let demoTask: ScheduledTask | null = null;
 
 function startDemoReset(): void {
   if (demoTask) { demoTask.stop(); demoTask = null; }
-  if (process.env.DEMO_MODE !== 'true') return;
+  if (process.env.DEMO_MODE?.toLowerCase() !== 'true') return;
 
   demoTask = cron.schedule('0 * * * *', () => {
     try {
diff --git a/server/src/services/adminService.ts b/server/src/services/adminService.ts
index 66a2d349..f0fc5420 100644
--- a/server/src/services/adminService.ts
+++ b/server/src/services/adminService.ts
@@ -8,6 +8,7 @@ import { updateJwtSecret } from '../config';
 import { maybe_encrypt_api_key, decrypt_api_key } from './apiKeyCrypto';
 import { getAllPermissions, savePermissions as savePerms, PERMISSION_ACTIONS } from './permissions';
 import { revokeUserSessions, revokeUserSessionsForClient } from '../mcp';
+import { deleteUserCompletely } from './userCleanupService';
 import { validatePassword } from './passwordPolicy';
 import { getPhotoProviderConfig } from './memories/helpersService';
 import { send as sendNotification } from './notificationService';
@@ -170,7 +171,7 @@ export function deleteUser(id: string, currentUserId: number) {
   const userToDel = db.prepare('SELECT id, email FROM users WHERE id = ?').get(id) as { id: number; email: string } | undefined;
   if (!userToDel) return { error: 'User not found', status: 404 };
 
-  db.prepare('DELETE FROM users WHERE id = ?').run(id);
+  deleteUserCompletely(userToDel.id);
   return { email: userToDel.email };
 }
 
@@ -287,7 +288,7 @@ export function updateOidcSettings(data: {
 // ── Demo Baseline ──────────────────────────────────────────────────────────
 
 export function saveDemoBaseline(): { error?: string; status?: number; message?: string } {
-  if (process.env.DEMO_MODE !== 'true') {
+  if (process.env.DEMO_MODE?.toLowerCase() !== 'true') {
     return { error: 'Not found', status: 404 };
   }
   try {
diff --git a/server/src/services/authService.ts b/server/src/services/authService.ts
index 3917e64b..ba949481 100644
--- a/server/src/services/authService.ts
+++ b/server/src/services/authService.ts
@@ -15,6 +15,7 @@ import { decrypt_api_key, maybe_encrypt_api_key, encrypt_api_key } from './apiKe
 import { createEphemeralToken } from './ephemeralTokens';
 import { revokeUserSessions } from '../mcp';
 import { startTripReminders } from '../scheduler';
+import { deleteUserCompletely } from './userCleanupService';
 import { verifyJwtAndLoadUser } from '../middleware/auth';
 import { User } from '../types';
 import { DEMO_EMAIL_PRIMARY, isDemoEmail } from './demo';
@@ -130,7 +131,7 @@ export function resolveAuthToggles(): {
       oidc_login: get('oidc_login') !== 'false',
       oidc_registration: get('oidc_registration') !== 'false',
     };
-    if (process.env.OIDC_ONLY === 'true') {
+    if (process.env.OIDC_ONLY?.toLowerCase() === 'true') {
       result.password_login = false;
       result.password_registration = false;
     }
@@ -138,7 +139,7 @@ export function resolveAuthToggles(): {
   }
 
   // Legacy fallback
-  const oidcOnlyEnabled = process.env.OIDC_ONLY === 'true' || get('oidc_only') === 'true';
+  const oidcOnlyEnabled = process.env.OIDC_ONLY?.toLowerCase() === 'true' || get('oidc_only') === 'true';
   const oidcConfigured = !!(
     (process.env.OIDC_ISSUER || get('oidc_issuer')) &&
     (process.env.OIDC_CLIENT_ID || get('oidc_client_id'))
@@ -252,7 +253,7 @@ export function getPendingMfaSecret(userId: number): string | null {
 
 export function getAppConfig(authenticatedUser: { id: number } | null) {
   const userCount = (db.prepare('SELECT COUNT(*) as count FROM users').get() as { count: number }).count;
-  const isDemo = process.env.DEMO_MODE === 'true';
+  const isDemo = process.env.DEMO_MODE?.toLowerCase() === 'true';
   const toggles = resolveAuthToggles();
   const version: string = process.env.APP_VERSION ?? require('../../package.json').version;
   const hasGoogleKey = !!db.prepare("SELECT maps_api_key FROM users WHERE role = 'admin' AND maps_api_key IS NOT NULL AND maps_api_key != '' LIMIT 1").get();
@@ -527,7 +528,7 @@ export function deleteAccount(userId: number, userEmail: string, userRole: strin
       return { error: 'Cannot delete the last admin account', status: 400 };
     }
   }
-  db.prepare('DELETE FROM users WHERE id = ?').run(userId);
+  deleteUserCompletely(userId);
   return { success: true };
 }
 
diff --git a/server/src/services/cookie.ts b/server/src/services/cookie.ts
index d1e88d2a..c97e187c 100644
--- a/server/src/services/cookie.ts
+++ b/server/src/services/cookie.ts
@@ -18,10 +18,10 @@ const COOKIE_NAME = 'trek_session';
  * remains the explicit escape hatch for plain-HTTP LAN testing.
  */
 export function cookieOptions(clear = false, req?: Request) {
-  if (process.env.COOKIE_SECURE === 'false') {
+  if (process.env.COOKIE_SECURE?.toLowerCase() === 'false') {
     return buildOptions(clear, false);
   }
-  const envSecure = process.env.NODE_ENV === 'production' || process.env.FORCE_HTTPS === 'true';
+  const envSecure = process.env.NODE_ENV?.toLowerCase() === 'production' || process.env.FORCE_HTTPS?.toLowerCase() === 'true';
   const requestSecure = req?.secure === true;
   return buildOptions(clear, envSecure || requestSecure);
 }
diff --git a/server/src/services/notificationService.ts b/server/src/services/notificationService.ts
index f14e48d8..67f02f2a 100644
--- a/server/src/services/notificationService.ts
+++ b/server/src/services/notificationService.ts
@@ -170,7 +170,7 @@ export async function send(payload: NotificationPayload): Promise<void> {
   const configEntry = EVENT_NOTIFICATION_CONFIG[event];
   if (!configEntry) {
     logDebug(`notificationService.send: unknown event type "${event}", using fallback`);
-    if (process.env.NODE_ENV === 'development' && actorId != null) {
+    if (process.env.NODE_ENV?.toLowerCase() === 'development' && actorId != null) {
       const devSender = (db.prepare('SELECT username, avatar FROM users WHERE id = ?').get(actorId) as { username: string; avatar: string | null } | undefined) ?? null;
       createNotificationForRecipient({
         type: 'simple',
diff --git a/server/src/services/tripService.ts b/server/src/services/tripService.ts
index 1f129d2e..5b37f49f 100644
--- a/server/src/services/tripService.ts
+++ b/server/src/services/tripService.ts
@@ -117,10 +117,11 @@ export function generateDays(tripId: number | bigint | string, startDate: string
     }
   }
 
-  // Overflow dated days (trip shrunk): convert to dateless instead of deleting
-  const nullify = db.prepare('UPDATE days SET date = NULL, day_number = ? WHERE id = ?');
+  // Overflow dated days (trip shrunk): delete them (issue #909).
+  // Cascade removes their assignments, notes, and accommodations.
+  const del = db.prepare('DELETE FROM days WHERE id = ?');
   for (let i = targetDates.length; i < dated.length; i++) {
-    nullify.run(targetDates.length + (i - targetDates.length) + 1, dated[i].id);
+    del.run(dated[i].id);
   }
 
   // Any remaining unused dateless days: keep as dateless, just renumber.
diff --git a/server/src/services/userCleanupService.ts b/server/src/services/userCleanupService.ts
new file mode 100644
index 00000000..84239449
--- /dev/null
+++ b/server/src/services/userCleanupService.ts
@@ -0,0 +1,21 @@
+import { db } from '../db/database';
+
+function cleanupUserReferences(userId: number): void {
+  db.prepare('UPDATE trip_members SET invited_by = NULL WHERE invited_by = ?').run(userId);
+  db.prepare('UPDATE budget_items SET paid_by_user_id = NULL WHERE paid_by_user_id = ?').run(userId);
+  db.prepare('DELETE FROM share_tokens WHERE created_by = ?').run(userId);
+  db.prepare('DELETE FROM journey_share_tokens WHERE created_by = ?').run(userId);
+  // Owned journeys cascade-delete their entries/contributors/share_tokens/photos via journey_id FKs
+  db.prepare('DELETE FROM journeys WHERE user_id = ?').run(userId);
+  // Entries authored on other users' journeys (not covered by the cascade above)
+  db.prepare('DELETE FROM journey_entries WHERE author_id = ?').run(userId);
+  db.prepare('DELETE FROM journey_contributors WHERE user_id = ?').run(userId);
+}
+
+export function deleteUserCompletely(userId: number): void {
+  const tx = db.transaction((id: number) => {
+    cleanupUserReferences(id);
+    db.prepare('DELETE FROM users WHERE id = ?').run(id);
+  });
+  tx(userId);
+}
diff --git a/server/src/utils/ssrfGuard.ts b/server/src/utils/ssrfGuard.ts
index d5f2aa3f..19ed98dc 100644
--- a/server/src/utils/ssrfGuard.ts
+++ b/server/src/utils/ssrfGuard.ts
@@ -1,7 +1,7 @@
 import dns from 'node:dns/promises';
 import { Agent } from 'undici';
 
-const ALLOW_INTERNAL_NETWORK = process.env.ALLOW_INTERNAL_NETWORK === 'true';
+const ALLOW_INTERNAL_NETWORK = process.env.ALLOW_INTERNAL_NETWORK?.toLowerCase() === 'true';
 
 export interface SsrfResult {
   allowed: boolean;
diff --git a/server/tests/integration/admin.test.ts b/server/tests/integration/admin.test.ts
index 0d105c61..beeaa0a1 100644
--- a/server/tests/integration/admin.test.ts
+++ b/server/tests/integration/admin.test.ts
@@ -41,7 +41,7 @@ import { createApp } from '../../src/app';
 import { createTables } from '../../src/db/schema';
 import { runMigrations } from '../../src/db/migrations';
 import { resetTestDb } from '../helpers/test-db';
-import { createUser, createAdmin, createInviteToken } from '../helpers/factories';
+import { createUser, createAdmin, createInviteToken, createTrip, createBudgetItem, createJourney, createJourneyEntry, addJourneyContributor, addTripPhoto, createCategory, createTag, createTodoItem, createMcpToken, createBucketListItem, createVisitedCountry, createCollabNote, addTripMember } from '../helpers/factories';
 import { authCookie } from '../helpers/auth';
 import { loginAttempts, mfaAttempts } from '../../src/routes/auth';
 
@@ -148,6 +148,216 @@ describe('Admin user management', () => {
     expect(deleted).toBeUndefined();
   });
 
+  it('ADMIN-005b — DELETE /admin/users/:id succeeds when user has FK references', async () => {
+    const { user: admin } = createAdmin(testDb);
+    const { user: target } = createUser(testDb);
+    const { user: otherUser } = createUser(testDb);
+    const { user: thirdUser } = createUser(testDb);
+
+    // trip_members.invited_by: target invited thirdUser to otherUser's trip
+    // (trip survives deletion; only invited_by should become NULL)
+    const otherTrip = createTrip(testDb, otherUser.id);
+    testDb.prepare('INSERT INTO trip_members (trip_id, user_id, invited_by) VALUES (?, ?, ?)').run(otherTrip.id, thirdUser.id, target.id);
+
+    // share_tokens.created_by: target created a share token for otherUser's trip
+    testDb.prepare("INSERT INTO share_tokens (trip_id, token, created_by) VALUES (?, 'tok-admin-test', ?)").run(otherTrip.id, target.id);
+
+    // budget_items.paid_by_user_id: target paid for an expense on otherUser's trip
+    const budgetItem = createBudgetItem(testDb, otherTrip.id);
+    testDb.prepare('UPDATE budget_items SET paid_by_user_id = ? WHERE id = ?').run(target.id, budgetItem.id);
+
+    // journey_contributors: target is a contributor on otherUser's journey
+    const otherJourney = createJourney(testDb, otherUser.id);
+    addJourneyContributor(testDb, otherJourney.id, target.id);
+
+    // journey_entries: target authored an entry on otherUser's journey
+    createJourneyEntry(testDb, otherJourney.id, target.id);
+
+    // journey_share_tokens: target created a share token for otherUser's journey
+    testDb.prepare("INSERT INTO journey_share_tokens (journey_id, token, created_by) VALUES (?, 'jst-admin-test', ?)").run(otherJourney.id, target.id);
+
+    // notifications.sender_id (SET NULL): target sent a notification to otherUser
+    const sentNotif = testDb.prepare(
+      "INSERT INTO notifications (type, scope, target, sender_id, recipient_id, title_key, text_key) VALUES ('simple', 'trip', ?, ?, ?, 'k', 'k')"
+    ).run(otherTrip.id, target.id, otherUser.id);
+    // notifications.recipient_id (CASCADE): otherUser sent a notification to target
+    testDb.prepare(
+      "INSERT INTO notifications (type, scope, target, sender_id, recipient_id, title_key, text_key) VALUES ('simple', 'trip', ?, ?, ?, 'k', 'k')"
+    ).run(otherTrip.id, otherUser.id, target.id);
+
+    // user_notice_dismissals (CASCADE): target dismissed a notice
+    testDb.prepare(
+      "INSERT INTO user_notice_dismissals (user_id, notice_id, dismissed_at) VALUES (?, 'test-notice', ?)"
+    ).run(target.id, Date.now());
+
+    // owned journey: target owns a journey with an entry (cascade-deletes on journey deletion)
+    const ownedJourney = createJourney(testDb, target.id);
+    createJourneyEntry(testDb, ownedJourney.id, target.id);
+
+    // trip_files.uploaded_by (SET NULL): target uploaded a file to otherUser's trip
+    const fileRow = testDb.prepare(
+      "INSERT INTO trip_files (trip_id, filename, original_name, uploaded_by) VALUES (?, 'f.pdf', 'file.pdf', ?)"
+    ).run(otherTrip.id, target.id);
+
+    // trek_photos.owner_id (SET NULL): target owns a photo in the central registry
+    const trekPhotoRow = testDb.prepare(
+      "INSERT INTO trek_photos (provider, asset_id, owner_id) VALUES ('immich', 'asset-admin-test', ?)"
+    ).run(target.id);
+
+    // trip_photos.user_id (CASCADE): target added a photo to otherUser's trip
+    addTripPhoto(testDb, otherTrip.id, target.id, 'asset-tp-admin', 'immich');
+
+    // trips.user_id (CASCADE): target owns a trip
+    const ownedTrip = createTrip(testDb, target.id);
+
+    // trip_members.user_id (CASCADE): target is a member of otherUser's trip
+    addTripMember(testDb, otherTrip.id, target.id);
+
+    // categories.user_id (SET NULL): target created a category
+    const userCategory = createCategory(testDb, { user_id: target.id });
+
+    // tags.user_id (CASCADE): target created a tag
+    const userTag = createTag(testDb, target.id);
+
+    // todo_items.assigned_user_id (SET NULL): target is assigned to a todo on otherUser's trip
+    const todoItem = createTodoItem(testDb, otherTrip.id);
+    testDb.prepare('UPDATE todo_items SET assigned_user_id = ? WHERE id = ?').run(target.id, todoItem.id);
+
+    // packing_bags.user_id (SET NULL): target owns a packing bag on otherUser's trip
+    const packBagRow = testDb.prepare(
+      "INSERT INTO packing_bags (trip_id, name, color, user_id) VALUES (?, 'Bag', '#ff0000', ?)"
+    ).run(otherTrip.id, target.id);
+
+    // mcp_tokens.user_id (CASCADE): target has an MCP API token
+    createMcpToken(testDb, target.id);
+
+    // oauth_tokens/consents.user_id (CASCADE): target has tokens from otherUser's OAuth client
+    testDb.prepare(
+      "INSERT INTO oauth_clients (id, user_id, name, client_id, client_secret_hash) VALUES ('cl-admin-test', ?, 'App', 'cid-admin-test', 'h')"
+    ).run(otherUser.id);
+    testDb.prepare(
+      "INSERT INTO oauth_tokens (client_id, user_id, access_token_hash, refresh_token_hash, access_token_expires_at, refresh_token_expires_at) VALUES ('cid-admin-test', ?, 'ath-admin', 'rth-admin', datetime('now','+1 hour'), datetime('now','+30 days'))"
+    ).run(target.id);
+    testDb.prepare(
+      "INSERT INTO oauth_consents (client_id, user_id) VALUES ('cid-admin-test', ?)"
+    ).run(target.id);
+
+    // vacay_plans.owner_id (CASCADE): target owns a vacation plan
+    const vacayPlanRow = testDb.prepare("INSERT INTO vacay_plans (owner_id) VALUES (?)").run(target.id);
+
+    // vacay_plan_members.user_id (CASCADE): target is a member of otherUser's vacay plan
+    const otherVacayPlanRow = testDb.prepare("INSERT INTO vacay_plans (owner_id) VALUES (?)").run(otherUser.id);
+    testDb.prepare("INSERT INTO vacay_plan_members (plan_id, user_id) VALUES (?, ?)").run(otherVacayPlanRow.lastInsertRowid, target.id);
+
+    // bucket_list.user_id (CASCADE): target has a bucket list item
+    createBucketListItem(testDb, target.id);
+
+    // visited_countries.user_id (CASCADE): target has visited a country
+    createVisitedCountry(testDb, target.id, 'JP');
+
+    // visited_regions.user_id (CASCADE): target has visited a region
+    testDb.prepare(
+      "INSERT INTO visited_regions (user_id, region_code, region_name, country_code) VALUES (?, 'JP-13', 'Tokyo', 'JP')"
+    ).run(target.id);
+
+    // packing_templates.created_by (CASCADE): target created a packing template
+    const packTemplateRow = testDb.prepare(
+      "INSERT INTO packing_templates (name, created_by) VALUES ('My Template', ?)"
+    ).run(target.id);
+
+    // invite_tokens.created_by (CASCADE): target created an invite token
+    createInviteToken(testDb, { created_by: target.id });
+
+    // collab_notes.user_id (CASCADE): target authored a collab note on otherUser's trip
+    createCollabNote(testDb, otherTrip.id, target.id);
+
+    // settings.user_id (CASCADE): target has a user setting
+    testDb.prepare("INSERT INTO settings (user_id, key, value) VALUES (?, 'theme', 'dark')").run(target.id);
+
+    // password_reset_tokens.user_id (CASCADE): target has a pending password reset
+    testDb.prepare(
+      "INSERT INTO password_reset_tokens (user_id, token_hash, expires_at) VALUES (?, 'prt-hash-admin', datetime('now','+1 hour'))"
+    ).run(target.id);
+
+    // audit_log.user_id (SET NULL): target performed an audited action
+    const auditRow = testDb.prepare(
+      "INSERT INTO audit_log (user_id, action, ip) VALUES (?, 'test.action', '127.0.0.1')"
+    ).run(target.id);
+
+    // notification_channel_preferences.user_id (CASCADE): target has notification preferences
+    testDb.prepare("INSERT OR IGNORE INTO notification_channel_preferences (user_id, event_type, channel) VALUES (?, 'trip_invite', 'email')").run(target.id);
+
+    const res = await request(app)
+      .delete(`/api/admin/users/${target.id}`)
+      .set('Cookie', authCookie(admin.id));
+    expect(res.status).toBe(200);
+    expect(res.body.success).toBe(true);
+
+    expect(testDb.prepare('SELECT id FROM users WHERE id = ?').get(target.id)).toBeUndefined();
+    // trip_members row survives but invited_by is now NULL
+    expect((testDb.prepare('SELECT invited_by FROM trip_members WHERE trip_id = ? AND user_id = ?').get(otherTrip.id, thirdUser.id) as any).invited_by).toBeNull();
+    expect(testDb.prepare('SELECT id FROM share_tokens WHERE created_by = ?').get(target.id)).toBeUndefined();
+    expect((testDb.prepare('SELECT paid_by_user_id FROM budget_items WHERE id = ?').get(budgetItem.id) as any).paid_by_user_id).toBeNull();
+    expect(testDb.prepare('SELECT user_id FROM journey_contributors WHERE journey_id = ? AND user_id = ?').get(otherJourney.id, target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM journey_entries WHERE author_id = ?').get(target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM journey_share_tokens WHERE created_by = ?').get(target.id)).toBeUndefined();
+    // sent notification survives but sender_id becomes NULL
+    expect((testDb.prepare('SELECT sender_id FROM notifications WHERE id = ?').get(sentNotif.lastInsertRowid) as any).sender_id).toBeNull();
+    // received notification is cascade-deleted
+    expect(testDb.prepare('SELECT id FROM notifications WHERE recipient_id = ?').get(target.id)).toBeUndefined();
+    // notice dismissals are cascade-deleted
+    expect(testDb.prepare("SELECT user_id FROM user_notice_dismissals WHERE user_id = ? AND notice_id = 'test-notice'").get(target.id)).toBeUndefined();
+    // owned journey and its entries are cascade-deleted
+    expect(testDb.prepare('SELECT id FROM journeys WHERE user_id = ?').get(target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM journey_entries WHERE journey_id = ?').get(ownedJourney.id)).toBeUndefined();
+    // uploaded file survives but uploaded_by is now NULL
+    expect((testDb.prepare('SELECT uploaded_by FROM trip_files WHERE id = ?').get(fileRow.lastInsertRowid) as any).uploaded_by).toBeNull();
+    // trek_photos row survives but owner_id is now NULL
+    expect((testDb.prepare('SELECT owner_id FROM trek_photos WHERE id = ?').get(trekPhotoRow.lastInsertRowid) as any).owner_id).toBeNull();
+    // trip_photos row for target is cascade-deleted
+    expect(testDb.prepare("SELECT id FROM trip_photos WHERE trip_id = ? AND user_id = ?").get(otherTrip.id, target.id)).toBeUndefined();
+    // owned trip is cascade-deleted
+    expect(testDb.prepare('SELECT id FROM trips WHERE id = ?').get(ownedTrip.id)).toBeUndefined();
+    // trip membership on others' trips is removed
+    expect(testDb.prepare('SELECT id FROM trip_members WHERE trip_id = ? AND user_id = ?').get(otherTrip.id, target.id)).toBeUndefined();
+    // category survives but user_id is NULL
+    expect((testDb.prepare('SELECT user_id FROM categories WHERE id = ?').get(userCategory.id) as any).user_id).toBeNull();
+    // tag is deleted
+    expect(testDb.prepare('SELECT id FROM tags WHERE id = ?').get(userTag.id)).toBeUndefined();
+    // todo assigned_user_id is NULL
+    expect((testDb.prepare('SELECT assigned_user_id FROM todo_items WHERE id = ?').get(todoItem.id) as any).assigned_user_id).toBeNull();
+    // packing bag survives but user_id is NULL
+    expect((testDb.prepare('SELECT user_id FROM packing_bags WHERE id = ?').get(packBagRow.lastInsertRowid) as any).user_id).toBeNull();
+    // MCP tokens are deleted
+    expect(testDb.prepare('SELECT id FROM mcp_tokens WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // OAuth tokens and consents are deleted
+    expect(testDb.prepare('SELECT id FROM oauth_tokens WHERE user_id = ?').get(target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM oauth_consents WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // owned vacay plan is deleted
+    expect(testDb.prepare('SELECT id FROM vacay_plans WHERE id = ?').get(vacayPlanRow.lastInsertRowid)).toBeUndefined();
+    // vacay plan membership on others' plans is removed
+    expect(testDb.prepare('SELECT id FROM vacay_plan_members WHERE plan_id = ? AND user_id = ?').get(otherVacayPlanRow.lastInsertRowid, target.id)).toBeUndefined();
+    // bucket list items are deleted
+    expect(testDb.prepare('SELECT id FROM bucket_list WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // travel history is deleted
+    expect(testDb.prepare('SELECT user_id FROM visited_countries WHERE user_id = ? AND country_code = ?').get(target.id, 'JP')).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM visited_regions WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // packing template is deleted
+    expect(testDb.prepare('SELECT id FROM packing_templates WHERE id = ?').get(packTemplateRow.lastInsertRowid)).toBeUndefined();
+    // invite tokens created by target are deleted
+    expect(testDb.prepare('SELECT id FROM invite_tokens WHERE created_by = ?').get(target.id)).toBeUndefined();
+    // collab content is deleted
+    expect(testDb.prepare('SELECT id FROM collab_notes WHERE user_id = ? AND trip_id = ?').get(target.id, otherTrip.id)).toBeUndefined();
+    // user settings are deleted
+    expect(testDb.prepare("SELECT id FROM settings WHERE user_id = ?").get(target.id)).toBeUndefined();
+    // password reset tokens are deleted
+    expect(testDb.prepare('SELECT id FROM password_reset_tokens WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // audit log entry survives but user_id is NULL
+    expect((testDb.prepare('SELECT user_id FROM audit_log WHERE id = ?').get(auditRow.lastInsertRowid) as any).user_id).toBeNull();
+    // notification channel preferences are deleted
+    expect(testDb.prepare("SELECT user_id FROM notification_channel_preferences WHERE user_id = ? AND event_type = 'trip_invite'").get(target.id)).toBeUndefined();
+  });
+
   it('ADMIN-006 — admin cannot delete their own account', async () => {
     const { user: admin } = createAdmin(testDb);
 
diff --git a/server/tests/integration/auth.test.ts b/server/tests/integration/auth.test.ts
index deb9df5a..d60dbc0e 100644
--- a/server/tests/integration/auth.test.ts
+++ b/server/tests/integration/auth.test.ts
@@ -52,7 +52,7 @@ import { createApp } from '../../src/app';
 import { createTables } from '../../src/db/schema';
 import { runMigrations } from '../../src/db/migrations';
 import { resetTestDb } from '../helpers/test-db';
-import { createUser, createAdmin, createUserWithMfa, createInviteToken } from '../helpers/factories';
+import { createUser, createAdmin, createUserWithMfa, createInviteToken, createTrip, createBudgetItem, createJourney, createJourneyEntry, addJourneyContributor, addTripPhoto, createCategory, createTag, createTodoItem, createMcpToken, createBucketListItem, createVisitedCountry, createCollabNote, addTripMember } from '../helpers/factories';
 import { authCookie, authHeader } from '../helpers/auth';
 import { loginAttempts, mfaAttempts } from '../../src/routes/auth';
 
@@ -509,6 +509,225 @@ describe('Extended auth scenarios', () => {
   });
 });
 
+// ─────────────────────────────────────────────────────────────────────────────
+// Account deletion
+// ─────────────────────────────────────────────────────────────────────────────
+
+describe('Account deletion', () => {
+  it('AUTH-040 — DELETE /auth/me succeeds when user has FK references', async () => {
+    const { user: admin } = createAdmin(testDb);
+    const { user: target } = createUser(testDb);
+    const { user: otherUser } = createUser(testDb);
+    const { user: thirdUser } = createUser(testDb);
+
+    // trip_members.invited_by: target invited thirdUser to otherUser's trip
+    // (trip survives deletion; only invited_by should become NULL)
+    const otherTrip = createTrip(testDb, otherUser.id);
+    testDb.prepare('INSERT INTO trip_members (trip_id, user_id, invited_by) VALUES (?, ?, ?)').run(otherTrip.id, thirdUser.id, target.id);
+
+    // share_tokens.created_by: target created a share token for otherUser's trip
+    testDb.prepare("INSERT INTO share_tokens (trip_id, token, created_by) VALUES (?, 'tok-auth-test', ?)").run(otherTrip.id, target.id);
+
+    // budget_items.paid_by_user_id: target paid for an expense on otherUser's trip
+    const budgetItem = createBudgetItem(testDb, otherTrip.id);
+    testDb.prepare('UPDATE budget_items SET paid_by_user_id = ? WHERE id = ?').run(target.id, budgetItem.id);
+
+    // journey_contributors: target is a contributor on otherUser's journey
+    const otherJourney = createJourney(testDb, otherUser.id);
+    addJourneyContributor(testDb, otherJourney.id, target.id);
+
+    // journey_entries: target authored an entry on otherUser's journey
+    createJourneyEntry(testDb, otherJourney.id, target.id);
+
+    // journey_share_tokens: target created a share token for otherUser's journey
+    testDb.prepare("INSERT INTO journey_share_tokens (journey_id, token, created_by) VALUES (?, 'jst-auth-test', ?)").run(otherJourney.id, target.id);
+
+    // notifications.sender_id (SET NULL): target sent a notification to otherUser
+    const sentNotif = testDb.prepare(
+      "INSERT INTO notifications (type, scope, target, sender_id, recipient_id, title_key, text_key) VALUES ('simple', 'trip', ?, ?, ?, 'k', 'k')"
+    ).run(otherTrip.id, target.id, otherUser.id);
+    // notifications.recipient_id (CASCADE): otherUser sent a notification to target
+    testDb.prepare(
+      "INSERT INTO notifications (type, scope, target, sender_id, recipient_id, title_key, text_key) VALUES ('simple', 'trip', ?, ?, ?, 'k', 'k')"
+    ).run(otherTrip.id, otherUser.id, target.id);
+
+    // user_notice_dismissals (CASCADE): target dismissed a notice
+    testDb.prepare(
+      "INSERT INTO user_notice_dismissals (user_id, notice_id, dismissed_at) VALUES (?, 'test-notice', ?)"
+    ).run(target.id, Date.now());
+
+    // owned journey: target owns a journey with an entry (cascade-deletes on journey deletion)
+    const ownedJourney = createJourney(testDb, target.id);
+    createJourneyEntry(testDb, ownedJourney.id, target.id);
+
+    // trip_files.uploaded_by (SET NULL): target uploaded a file to otherUser's trip
+    const fileRow = testDb.prepare(
+      "INSERT INTO trip_files (trip_id, filename, original_name, uploaded_by) VALUES (?, 'f.pdf', 'file.pdf', ?)"
+    ).run(otherTrip.id, target.id);
+
+    // trek_photos.owner_id (SET NULL): target owns a photo in the central registry
+    const trekPhotoRow = testDb.prepare(
+      "INSERT INTO trek_photos (provider, asset_id, owner_id) VALUES ('immich', 'asset-auth-test', ?)"
+    ).run(target.id);
+
+    // trip_photos.user_id (CASCADE): target added a photo to otherUser's trip
+    addTripPhoto(testDb, otherTrip.id, target.id, 'asset-tp-auth', 'immich');
+
+    // trips.user_id (CASCADE): target owns a trip
+    const ownedTrip = createTrip(testDb, target.id);
+
+    // trip_members.user_id (CASCADE): target is a member of otherUser's trip
+    addTripMember(testDb, otherTrip.id, target.id);
+
+    // categories.user_id (SET NULL): target created a category
+    const userCategory = createCategory(testDb, { user_id: target.id });
+
+    // tags.user_id (CASCADE): target created a tag
+    const userTag = createTag(testDb, target.id);
+
+    // todo_items.assigned_user_id (SET NULL): target is assigned to a todo on otherUser's trip
+    const todoItem = createTodoItem(testDb, otherTrip.id);
+    testDb.prepare('UPDATE todo_items SET assigned_user_id = ? WHERE id = ?').run(target.id, todoItem.id);
+
+    // packing_bags.user_id (SET NULL): target owns a packing bag on otherUser's trip
+    const packBagRow = testDb.prepare(
+      "INSERT INTO packing_bags (trip_id, name, color, user_id) VALUES (?, 'Bag', '#ff0000', ?)"
+    ).run(otherTrip.id, target.id);
+
+    // mcp_tokens.user_id (CASCADE): target has an MCP API token
+    createMcpToken(testDb, target.id);
+
+    // oauth_tokens/consents.user_id (CASCADE): target has tokens from otherUser's OAuth client
+    testDb.prepare(
+      "INSERT INTO oauth_clients (id, user_id, name, client_id, client_secret_hash) VALUES ('cl-auth-test', ?, 'App', 'cid-auth-test', 'h')"
+    ).run(otherUser.id);
+    testDb.prepare(
+      "INSERT INTO oauth_tokens (client_id, user_id, access_token_hash, refresh_token_hash, access_token_expires_at, refresh_token_expires_at) VALUES ('cid-auth-test', ?, 'ath-auth', 'rth-auth', datetime('now','+1 hour'), datetime('now','+30 days'))"
+    ).run(target.id);
+    testDb.prepare(
+      "INSERT INTO oauth_consents (client_id, user_id) VALUES ('cid-auth-test', ?)"
+    ).run(target.id);
+
+    // vacay_plans.owner_id (CASCADE): target owns a vacation plan
+    const vacayPlanRow = testDb.prepare("INSERT INTO vacay_plans (owner_id) VALUES (?)").run(target.id);
+
+    // vacay_plan_members.user_id (CASCADE): target is a member of otherUser's vacay plan
+    const otherVacayPlanRow = testDb.prepare("INSERT INTO vacay_plans (owner_id) VALUES (?)").run(otherUser.id);
+    testDb.prepare("INSERT INTO vacay_plan_members (plan_id, user_id) VALUES (?, ?)").run(otherVacayPlanRow.lastInsertRowid, target.id);
+
+    // bucket_list.user_id (CASCADE): target has a bucket list item
+    createBucketListItem(testDb, target.id);
+
+    // visited_countries.user_id (CASCADE): target has visited a country
+    createVisitedCountry(testDb, target.id, 'JP');
+
+    // visited_regions.user_id (CASCADE): target has visited a region
+    testDb.prepare(
+      "INSERT INTO visited_regions (user_id, region_code, region_name, country_code) VALUES (?, 'JP-13', 'Tokyo', 'JP')"
+    ).run(target.id);
+
+    // packing_templates.created_by (CASCADE): target created a packing template
+    const packTemplateRow = testDb.prepare(
+      "INSERT INTO packing_templates (name, created_by) VALUES ('My Template', ?)"
+    ).run(target.id);
+
+    // invite_tokens.created_by (CASCADE): target created an invite token
+    createInviteToken(testDb, { created_by: target.id });
+
+    // collab_notes.user_id (CASCADE): target authored a collab note on otherUser's trip
+    createCollabNote(testDb, otherTrip.id, target.id);
+
+    // settings.user_id (CASCADE): target has a user setting
+    testDb.prepare("INSERT INTO settings (user_id, key, value) VALUES (?, 'theme', 'dark')").run(target.id);
+
+    // password_reset_tokens.user_id (CASCADE): target has a pending password reset
+    testDb.prepare(
+      "INSERT INTO password_reset_tokens (user_id, token_hash, expires_at) VALUES (?, 'prt-hash-auth', datetime('now','+1 hour'))"
+    ).run(target.id);
+
+    // audit_log.user_id (SET NULL): target performed an audited action
+    const auditRow = testDb.prepare(
+      "INSERT INTO audit_log (user_id, action, ip) VALUES (?, 'test.action', '127.0.0.1')"
+    ).run(target.id);
+
+    // notification_channel_preferences.user_id (CASCADE): target has notification preferences
+    testDb.prepare("INSERT OR IGNORE INTO notification_channel_preferences (user_id, event_type, channel) VALUES (?, 'trip_invite', 'email')").run(target.id);
+
+    // admin exists to ensure target (non-admin user) passes the last-admin guard
+    void admin;
+
+    const res = await request(app)
+      .delete('/api/auth/me')
+      .set('Cookie', authCookie(target.id));
+    expect(res.status).toBe(200);
+    expect(res.body.success).toBe(true);
+
+    expect(testDb.prepare('SELECT id FROM users WHERE id = ?').get(target.id)).toBeUndefined();
+    // trip_members row survives but invited_by is now NULL
+    expect((testDb.prepare('SELECT invited_by FROM trip_members WHERE trip_id = ? AND user_id = ?').get(otherTrip.id, thirdUser.id) as any).invited_by).toBeNull();
+    expect(testDb.prepare('SELECT id FROM share_tokens WHERE created_by = ?').get(target.id)).toBeUndefined();
+    expect((testDb.prepare('SELECT paid_by_user_id FROM budget_items WHERE id = ?').get(budgetItem.id) as any).paid_by_user_id).toBeNull();
+    expect(testDb.prepare('SELECT user_id FROM journey_contributors WHERE journey_id = ? AND user_id = ?').get(otherJourney.id, target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM journey_entries WHERE author_id = ?').get(target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM journey_share_tokens WHERE created_by = ?').get(target.id)).toBeUndefined();
+    // sent notification survives but sender_id becomes NULL
+    expect((testDb.prepare('SELECT sender_id FROM notifications WHERE id = ?').get(sentNotif.lastInsertRowid) as any).sender_id).toBeNull();
+    // received notification is cascade-deleted
+    expect(testDb.prepare('SELECT id FROM notifications WHERE recipient_id = ?').get(target.id)).toBeUndefined();
+    // notice dismissals are cascade-deleted
+    expect(testDb.prepare("SELECT user_id FROM user_notice_dismissals WHERE user_id = ? AND notice_id = 'test-notice'").get(target.id)).toBeUndefined();
+    // owned journey and its entries are cascade-deleted
+    expect(testDb.prepare('SELECT id FROM journeys WHERE user_id = ?').get(target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM journey_entries WHERE journey_id = ?').get(ownedJourney.id)).toBeUndefined();
+    // uploaded file survives but uploaded_by is now NULL
+    expect((testDb.prepare('SELECT uploaded_by FROM trip_files WHERE id = ?').get(fileRow.lastInsertRowid) as any).uploaded_by).toBeNull();
+    // trek_photos row survives but owner_id is now NULL
+    expect((testDb.prepare('SELECT owner_id FROM trek_photos WHERE id = ?').get(trekPhotoRow.lastInsertRowid) as any).owner_id).toBeNull();
+    // trip_photos row for target is cascade-deleted
+    expect(testDb.prepare("SELECT id FROM trip_photos WHERE trip_id = ? AND user_id = ?").get(otherTrip.id, target.id)).toBeUndefined();
+    // owned trip is cascade-deleted
+    expect(testDb.prepare('SELECT id FROM trips WHERE id = ?').get(ownedTrip.id)).toBeUndefined();
+    // trip membership on others' trips is removed
+    expect(testDb.prepare('SELECT id FROM trip_members WHERE trip_id = ? AND user_id = ?').get(otherTrip.id, target.id)).toBeUndefined();
+    // category survives but user_id is NULL
+    expect((testDb.prepare('SELECT user_id FROM categories WHERE id = ?').get(userCategory.id) as any).user_id).toBeNull();
+    // tag is deleted
+    expect(testDb.prepare('SELECT id FROM tags WHERE id = ?').get(userTag.id)).toBeUndefined();
+    // todo assigned_user_id is NULL
+    expect((testDb.prepare('SELECT assigned_user_id FROM todo_items WHERE id = ?').get(todoItem.id) as any).assigned_user_id).toBeNull();
+    // packing bag survives but user_id is NULL
+    expect((testDb.prepare('SELECT user_id FROM packing_bags WHERE id = ?').get(packBagRow.lastInsertRowid) as any).user_id).toBeNull();
+    // MCP tokens are deleted
+    expect(testDb.prepare('SELECT id FROM mcp_tokens WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // OAuth tokens and consents are deleted
+    expect(testDb.prepare('SELECT id FROM oauth_tokens WHERE user_id = ?').get(target.id)).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM oauth_consents WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // owned vacay plan is deleted
+    expect(testDb.prepare('SELECT id FROM vacay_plans WHERE id = ?').get(vacayPlanRow.lastInsertRowid)).toBeUndefined();
+    // vacay plan membership on others' plans is removed
+    expect(testDb.prepare('SELECT id FROM vacay_plan_members WHERE plan_id = ? AND user_id = ?').get(otherVacayPlanRow.lastInsertRowid, target.id)).toBeUndefined();
+    // bucket list items are deleted
+    expect(testDb.prepare('SELECT id FROM bucket_list WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // travel history is deleted
+    expect(testDb.prepare('SELECT user_id FROM visited_countries WHERE user_id = ? AND country_code = ?').get(target.id, 'JP')).toBeUndefined();
+    expect(testDb.prepare('SELECT id FROM visited_regions WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // packing template is deleted
+    expect(testDb.prepare('SELECT id FROM packing_templates WHERE id = ?').get(packTemplateRow.lastInsertRowid)).toBeUndefined();
+    // invite tokens created by target are deleted
+    expect(testDb.prepare('SELECT id FROM invite_tokens WHERE created_by = ?').get(target.id)).toBeUndefined();
+    // collab content is deleted
+    expect(testDb.prepare('SELECT id FROM collab_notes WHERE user_id = ? AND trip_id = ?').get(target.id, otherTrip.id)).toBeUndefined();
+    // user settings are deleted
+    expect(testDb.prepare("SELECT id FROM settings WHERE user_id = ?").get(target.id)).toBeUndefined();
+    // password reset tokens are deleted
+    expect(testDb.prepare('SELECT id FROM password_reset_tokens WHERE user_id = ?').get(target.id)).toBeUndefined();
+    // audit log entry survives but user_id is NULL
+    expect((testDb.prepare('SELECT user_id FROM audit_log WHERE id = ?').get(auditRow.lastInsertRowid) as any).user_id).toBeNull();
+    // notification channel preferences are deleted
+    expect(testDb.prepare("SELECT user_id FROM notification_channel_preferences WHERE user_id = ? AND event_type = 'trip_invite'").get(target.id)).toBeUndefined();
+  });
+});
+
 // ─────────────────────────────────────────────────────────────────────────────
 // Rate limiting (AUTH-004, AUTH-018) — placed last
 // ─────────────────────────────────────────────────────────────────────────────
diff --git a/server/tests/unit/services/tripService.test.ts b/server/tests/unit/services/tripService.test.ts
index 12c5a13d..795dbcb2 100644
--- a/server/tests/unit/services/tripService.test.ts
+++ b/server/tests/unit/services/tripService.test.ts
@@ -96,33 +96,37 @@ describe('generateDays', () => {
     expect(getNotes(day2.id)[0].id).toBe(note.id);
   });
 
-  it('TRIP-SVC-011: shrinking range converts overflow days to dateless, preserves their assignments', () => {
+  it('TRIP-SVC-011: shrinking range deletes overflow days and their assignments (issue #909)', () => {
     const { user } = createUser(testDb);
     const trip = createTrip(testDb, user.id, { start_date: '2025-07-01', end_date: '2025-07-05' });
     const daysBefore = getDays(trip.id);
     expect(daysBefore).toHaveLength(5);
 
     const place = createPlace(testDb, trip.id);
-    // Assign places to days 4 and 5 (will become overflow)
-    const a4 = createDayAssignment(testDb, daysBefore[3].id, place.id);
-    const a5 = createDayAssignment(testDb, daysBefore[4].id, place.id);
+    createDayAssignment(testDb, daysBefore[3].id, place.id);
+    createDayAssignment(testDb, daysBefore[4].id, place.id);
 
-    // Shrink from 5 to 3 days
+    // Shrink from 5 to 3 days — surplus days and their content are removed
     generateDays(trip.id, '2025-07-01', '2025-07-03');
 
     const daysAfter = getDays(trip.id);
-    expect(daysAfter).toHaveLength(5); // no rows deleted
+    expect(daysAfter).toHaveLength(3);
+    expect(daysAfter.map(d => d.date)).toEqual(['2025-07-01', '2025-07-02', '2025-07-03']);
+  });
 
-    const dated = daysAfter.filter(d => d.date !== null);
-    const dateless = daysAfter.filter(d => d.date === null);
-    expect(dated).toHaveLength(3);
-    expect(dateless).toHaveLength(2);
+  it('TRIP-SVC-016: shrinking range deletes empty overflow days (issue #909)', () => {
+    const { user } = createUser(testDb);
+    const trip = createTrip(testDb, user.id, { start_date: '2025-07-01', end_date: '2025-07-07' });
+    expect(getDays(trip.id)).toHaveLength(7);
 
-    // Overflow days still have their assignments
-    expect(getAssignments(dateless[0].id)).toHaveLength(1);
-    expect(getAssignments(dateless[0].id)[0].id).toBe(a4.id);
-    expect(getAssignments(dateless[1].id)).toHaveLength(1);
-    expect(getAssignments(dateless[1].id)[0].id).toBe(a5.id);
+    // Shrink 7 → 5; days 6 and 7 have no content
+    generateDays(trip.id, '2025-07-01', '2025-07-05');
+
+    const daysAfter = getDays(trip.id);
+    expect(daysAfter).toHaveLength(5);
+    expect(daysAfter.map(d => d.date)).toEqual([
+      '2025-07-01', '2025-07-02', '2025-07-03', '2025-07-04', '2025-07-05',
+    ]);
   });
 
   it('TRIP-SVC-012: growing range keeps existing day content and appends new empty days', () => {