fix: correct imports and add ESLint CI

- Fix proxy.js: use utils/config/service-helpers (correct path for
  Homepage v1.7.0; utils/service-helpers does not exist)
- Fix component.jsx: blank line between external and utils/ imports
  as required by Homepage ESLint import/order rule
- Add .eslintrc.json mirroring Homepage's ESLint config
- Add package.json with ESLint dev dependencies
- Add Forgejo Actions workflow to lint on push/PR

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

.forgejo/workflows/lint.yaml

@@ -0,0 +1,23 @@
+name: Lint
+
+on:
+  push:
+    branches: [master, main]
+  pull_request:
+
+jobs:
+  eslint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run ESLint
+        run: npm run lint