Fix: the server crashed on every Search; Search now covers tasks and events and explains itself

- Restore ddgAnswer, which an earlier edit deleted: /api/ddg threw a ReferenceError and killed the
  whole server process whenever Search ran
- One failing request can no longer take the server down (errors are logged and answered with a 500)
- tools/smoke-test.js starts the real server and calls every endpoint; the Gitea workflow runs it before
  building the image, so a missing function or a crash stops the build
- Search: also searches NE Hub tasks and calendar events; Seafile file search falls back to scanning file
  names when the search index returns nothing; Plex search falls back to the library's artists/albums;
  a status line shows what was searched, per-source counts and errors, with sign-in links

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -12,6 +12,13 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      # Start the real server and call every endpoint; a missing function or a crash stops the build here.
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      - run: npm ci
+      - run: node tools/smoke-test.js
+
       - uses: docker/setup-buildx-action@v3
 
       # Repo secrets needed (Settings -> Actions -> Secrets):