fix(journey): serve local file when uploading photos with Immich sync enabled

After upload, trek_photos.provider is immediately flipped to 'immich' even
though Immich's thumbnail generation is async. streamPhoto then routed to
Immich, which returned an error for the not-yet-processed asset. Because
Cache-Control was set before the proxy attempt, the error response was cached
by the browser for 24h — breaking thumbnails until a hard refresh bypassed
the cache and Immich had finished processing.

- streamPhoto now prefers the local file_path when it exists on disk,
  regardless of provider; Immich/Synology are only used when no local
  file is available (fixes the immediate broken-thumbnail symptom)
- pipeAsset sets Cache-Control: no-store on upstream errors and uses the
  caller-supplied default only on success (prevents cache poisoning)
- streamImmichAsset no longer pre-sets Cache-Control before the proxy
- streamSynologyAsset passes the same defaultCacheControl through pipeAsset

Closes #691

server/src/services/memories/helpersService.ts

@@ -253,13 +253,19 @@ export function updateSyncTimeForAlbumLink(linkId: string): void {
     db.prepare('UPDATE trip_album_links SET last_synced_at = CURRENT_TIMESTAMP WHERE id = ?').run(linkId);
 }
 
-export async function pipeAsset(url: string, response: Response, headers?: Record<string, string>, signal?: AbortSignal): Promise<void> {
+export async function pipeAsset(url: string, response: Response, headers?: Record<string, string>, signal?: AbortSignal, defaultCacheControl?: string): Promise<void> {
     try {
         const resp = await safeFetch(url, { headers, signal: signal as any });
 
         response.status(resp.status);
         if (resp.headers.get('content-type')) response.set('Content-Type', resp.headers.get('content-type') as string);
-        if (resp.headers.get('cache-control')) response.set('Cache-Control', resp.headers.get('cache-control') as string);
+        if (!resp.ok) {
+            response.set('Cache-Control', 'no-store, max-age=0');
+        } else if (resp.headers.get('cache-control')) {
+            response.set('Cache-Control', resp.headers.get('cache-control') as string);
+        } else if (defaultCacheControl) {
+            response.set('Cache-Control', defaultCacheControl);
+        }
         if (resp.headers.get('content-length')) response.set('Content-Length', resp.headers.get('content-length') as string);
         if (resp.headers.get('content-disposition')) response.set('Content-Disposition', resp.headers.get('content-disposition') as string);
 

server/src/services/memories/immichService.ts

@@ -246,8 +246,7 @@ export async function streamImmichAsset(
     ? `${creds.immich_url}/api/assets/${assetId}/thumbnail?size=thumbnail`
     : `${creds.immich_url}/api/assets/${assetId}/thumbnail?size=fullsize`;
 
-  response.set('Cache-Control', 'public, max-age=86400');
+  await pipeAsset(url, response, { 'x-api-key': creds.immich_api_key }, AbortSignal.timeout(timeout), 'public, max-age=86400');
-  await pipeAsset(url, response, { 'x-api-key': creds.immich_api_key }, AbortSignal.timeout(timeout));
 }
 
 // ── Albums ──────────────────────────────────────────────────────────────────

server/src/services/memories/photoResolverService.ts

@@ -69,15 +69,18 @@ export async function streamPhoto(
     return;
   }
 
+  if (photo.file_path) {
+    const localPath = path.join(__dirname, '../../../uploads', photo.file_path);
+    if (fs.existsSync(localPath)) {
+      res.set('Cache-Control', 'public, max-age=86400');
+      res.sendFile(localPath);
+      return;
+    }
+  }
+
   switch (photo.provider) {
     case 'local': {
-      const filePath = path.join(__dirname, '../../../uploads', photo.file_path!);
+      res.status(404).json({ error: 'File not found' });
-      if (!fs.existsSync(filePath)) {
-        res.status(404).json({ error: 'File not found' });
-        return;
-      }
-      res.set('Cache-Control', 'public, max-age=86400');
-      res.sendFile(filePath);
       return;
     }
     case 'immich': {

server/src/services/memories/synologyService.ts

@@ -661,6 +661,6 @@ export async function streamSynologyAsset(
     if (passphrase) params.append('passphrase', passphrase);
 
     const url = _buildSynologyEndpoint(synology_credentials.data.synology_url, params.toString());
-    await pipeAsset(url, response)
+    await pipeAsset(url, response, undefined, undefined, 'public, max-age=86400')
 }