fix(server): fix the quirks preserved by the budget DI migration

server/tests/unit/mcp/tools-budget-advanced.test.ts

@@ -83,7 +83,13 @@ describe('Tool: set_budget_item_members', () => {
       // Regression: returns a hydrated item, not the raw row from updateMembers.
       expect(data.item.members.map((m: any) => m.user_id)).toEqual([user.id]);
       expect(Array.isArray(data.item.payers)).toBe(true);
-      expect(broadcastMock).toHaveBeenCalledWith(trip.id, 'budget:members-updated', expect.any(Object));
+      // Quirk fix: the broadcast carries the REST payload shape (the legacy
+      // MCP-specific { item } shape was a silent no-op in the client handler).
+      expect(broadcastMock).toHaveBeenCalledWith(trip.id, 'budget:members-updated', expect.objectContaining({
+        itemId: item.id,
+        members: expect.arrayContaining([expect.objectContaining({ user_id: user.id })]),
+        persons: 1,
+      }));
     });
   });
 
@@ -215,7 +221,9 @@ describe('Tool: toggle_budget_member_paid', () => {
       });
       const data = parseToolResult(result) as any;
       expect(data.member).toBeDefined();
-      expect(broadcastMock).toHaveBeenCalledWith(trip.id, 'budget:member-paid-updated', expect.any(Object));
+      // Quirk fix: the broadcast carries the REST payload shape (the legacy
+      // MCP-specific { itemId, member } shape was a silent no-op in the client).
+      expect(broadcastMock).toHaveBeenCalledWith(trip.id, 'budget:member-paid-updated', expect.objectContaining({ itemId: item.id, userId: user.id, paid: 1 }));
     });
   });
 

server/tests/unit/nest/budget.service.calc.test.ts

@@ -485,9 +485,11 @@ describe('applySettlementUpdate', () => {
         return { get: vi.fn(), all: vi.fn(), run };
       }
       if (sql.includes('FROM budget_settlements')) {
-        return { get: vi.fn(), all: vi.fn(() => [
-          { id: 7, trip_id: 1, from_user_id: 2, to_user_id: 1, amount: 10.13, from_username: 'bob', to_username: 'alice', from_avatar: null, to_avatar: null },
-        ]), run: vi.fn() };
+        // Quirk fix: the re-select is a targeted single-row get, not a full
+        // listSettlements scan.
+        return { get: vi.fn(() => (
+          { id: 7, trip_id: 1, from_user_id: 2, to_user_id: 1, amount: 10.13, from_username: 'bob', to_username: 'alice', from_avatar: null, to_avatar: null }
+        )), all: vi.fn(() => []), run: vi.fn() };
       }
       return { get: vi.fn(), all: vi.fn(() => []), run: vi.fn() };
     });

server/tests/unit/nest/budget.service.db.test.ts

@@ -3,7 +3,9 @@
  * Uses a real in-memory SQLite DB so the SQL WHERE clauses are exercised.
  * BUDGET-SVC-DB-001 through 014 moved 1:1 from the legacy
  * tests/unit/services/budgetServiceDb.test.ts; 015–018 pin the budget.bridge
- * delegation (the bridge instance runs over the same mocked db Proxy).
+ * delegation (the bridge instance runs over the same mocked db Proxy);
+ * 019–020 pin the post-fold quirk fixes (COALESCE(display_name) on
+ * settlements, transactional multi-statement writes).
  */
 import { describe, it, expect, vi, beforeAll, beforeEach, afterAll } from 'vitest';
 
@@ -421,3 +423,30 @@ describe('budget.bridge delegation', () => {
     expect(row.reservation_id).toBe(reservationId);
   });
 });
+
+describe('post-fold quirk fixes', () => {
+  it('BUDGET-SVC-DB-019: settlements prefer display_name over username (quirk fix)', () => {
+    const { user: alice } = createUser(testDb, { username: 'alice' });
+    const { user: bob } = createUser(testDb, { username: 'bob' });
+    testDb.prepare('UPDATE users SET display_name = ? WHERE id = ?').run('Alice Displayed', alice.id);
+    const trip = createTrip(testDb, alice.id);
+
+    const created = budget.insertSettlement(trip.id, { from_user_id: alice.id, to_user_id: bob.id, amount: 10 }, alice.id);
+
+    expect(created!.from_username).toBe('Alice Displayed');
+    expect(created!.to_username).toBe('bob');
+    expect(budget.listSettlements(trip.id)[0].from_username).toBe('Alice Displayed');
+  });
+
+  it('BUDGET-SVC-DB-020: a failing item insert rolls back the category-order side write (quirk fix)', () => {
+    const { user } = createUser(testDb);
+    const trip = createTrip(testDb, user.id);
+
+    // NOT NULL violation on name fires after the category-order upsert — the
+    // legacy non-transactional create leaked the budget_category_order row.
+    expect(() => budget.createBudgetItem(trip.id, { name: null as unknown as string, category: 'atomic-test' })).toThrow();
+
+    const cat = testDb.prepare("SELECT 1 FROM budget_category_order WHERE trip_id = ? AND category = 'atomic-test'").get(trip.id);
+    expect(cat).toBeUndefined();
+  });
+});

server/tests/unit/nest/budget.service.test.ts

@@ -150,10 +150,13 @@ describe('BudgetService', () => {
     it('updateSettlement threads the stored currency through the freeze', async () => {
       const s = svc();
       const freezeSpy = vi.spyOn(s, 'freezeForeignRate').mockResolvedValue();
-      vi.spyOn(s, 'listSettlements').mockReturnValue([{ id: 7, currency: 'USD' }] as never);
+      // Quirk fix: the stored-currency lookup is a targeted getSettlement, not
+      // a full listSettlements scan.
+      const getSpy = vi.spyOn(s, 'getSettlement').mockReturnValue({ id: 7, currency: 'USD' } as never);
       const applySpy = vi.spyOn(s, 'applySettlementUpdate').mockReturnValue({ id: 7 } as never);
       await s.updateSettlement('7', '5', { from_user_id: 1, to_user_id: 2, amount: 12, currency: 'USD' });
       // the settlement's stored currency is threaded through so an unchanged-currency edit keeps the frozen rate (#1445)
+      expect(getSpy).toHaveBeenCalledWith('7', '5');
       expect(freezeSpy).toHaveBeenCalledWith('5', { from_user_id: 1, to_user_id: 2, amount: 12, currency: 'USD' }, undefined, 'USD');
       expect(applySpy).toHaveBeenCalledWith('7', '5', { from_user_id: 1, to_user_id: 2, amount: 12, currency: 'USD' });
     });