Fix CI: use npm install instead of npm ci

npm ci fails when the lock file is missing platform-specific packages
(yaml@2.8.3) that only get resolved on Linux. Switch to npm install
which resolves dependencies at runtime rather than strictly validating
the lock file.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -33,12 +33,10 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           node-version-file: .node-version
-          cache: npm
-          cache-dependency-path: web/package-lock.json
 
       - name: Install dependencies
         working-directory: web
-        run: npm ci
+        run: npm install
 
       - name: Type check
         working-directory: web