ci: install Node + build web before Go steps

Go's //go:embed needs web/build/ to exist at compile time. CI now
runs 'npm ci && npm run build && npm test' ahead of the Go steps
so the embed directive sees real, freshly-built assets.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.forgejo/workflows/test.yml

@@ -1,7 +1,7 @@
 name: test
 
-# Lint + short unit tests only. Integration tests needing Postgres/ffmpeg
-# run locally via docker-compose; they should guard with testing.Short().
+# Lint + short unit tests. Integration tests needing Postgres/ffmpeg run
+# locally via docker-compose; they should guard with testing.Short().
 
 on:
   push:
@@ -17,6 +17,25 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'npm'
+          cache-dependency-path: web/package-lock.json
+
+      - name: Install web deps
+        working-directory: web
+        run: npm ci
+
+      - name: Web build (populates web/build/ for go:embed)
+        working-directory: web
+        run: npm run build
+
+      - name: Web test (vitest)
+        working-directory: web
+        run: npm test
+
       - name: Detect Go project
         id: gomod
         shell: bash