feat(observability): add GlitchTip source map uploads for un-minified stack traces

- Enable sourcemap:true in vite.config.ts
- Add sentryVitePlugin: uploads maps to errors.libnovel.cc, deletes them post-upload so they never ship in the Docker image
- Wire release: PUBLIC_BUILD_VERSION in both hooks.client.ts and hooks.server.ts so events correlate to the correct artifact
- Add upload-sourcemaps CI job in release.yaml (parallel to docker-ui, uses GLITCHTIP_AUTH_TOKEN secret)

.gitea/workflows/release.yaml

@@ -135,6 +135,35 @@ jobs:
           cache-from: type=registry,ref=${{ secrets.DOCKER_USER }}/libnovel-runner:latest
           cache-to: type=inline
 
+  # ── ui: source map upload ─────────────────────────────────────────────────────
+  # Builds the UI with source maps and uploads them to GlitchTip so that error
+  # stack traces resolve to original .svelte/.ts file names and line numbers.
+  # Runs in parallel with docker-ui (both need check-ui to pass first).
+  upload-sourcemaps:
+    name: Upload source maps
+    runs-on: ubuntu-latest
+    needs: [check-ui]
+    defaults:
+      run:
+        working-directory: ui
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: npm
+          cache-dependency-path: ui/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build with source maps and upload to GlitchTip
+        env:
+          SENTRY_AUTH_TOKEN: ${{ secrets.GLITCHTIP_AUTH_TOKEN }}
+          BUILD_VERSION: ${{ gitea.ref_name }}
+        run: npm run build
+
   # ── docker: ui ────────────────────────────────────────────────────────────────
   docker-ui:
     name: Docker / ui
@@ -213,7 +242,7 @@ jobs:
   release:
     name: Gitea Release
     runs-on: ubuntu-latest
-    needs: [docker-backend, docker-runner, docker-ui, docker-caddy]
+    needs: [docker-backend, docker-runner, docker-ui, docker-caddy, upload-sourcemaps]
     steps:
       - uses: actions/checkout@v4
         with: