refactor: modernize codebase, remove Angular and legacy dependencies

- Remove Angular 1.x, jQuery, Gulp, Bower, Skel framework
- Replace with vanilla JS (app.js, gauge.js, i18n.js)
- Add runtime i18n with ?lang= query param support
- Simplify CSS from ~4000 to ~900 lines
- Add simple Node.js build script (scripts/build.js)
- Convert .po translations to JSON format
- Update GitHub Actions workflows for new build
- Change Firebase public dir from app/ to dist/

Dependencies reduced from ~680 to 13 packages.

Author: robertodauria

.github/workflows/firebase-hosting-merge.yml

@@ -14,9 +14,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - run: npm install -g yarn && yarn install --frozen-lockfile && yarn build
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+      - run: npm ci
+      - run: npm run build
       - name: Substitute M-Lab project placeholder
-        run: sed -i 's/MLAB_PROJECT_PLACEHOLDER/mlab-oti/g' app/measure/measure.js
+        run: sed -i 's/MLAB_PROJECT_PLACEHOLDER/mlab-oti/g' dist/js/app.js
       - uses: FirebaseExtended/action-hosting-deploy@v0
         with:
           repoToken: '${{ secrets.GITHUB_TOKEN }}'

.github/workflows/firebase-hosting-pull-request.yml

@@ -12,7 +12,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - run: npm install -g yarn && yarn install --frozen-lockfile && yarn build
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+      - run: npm ci
+      - run: npm run build
       - uses: FirebaseExtended/action-hosting-deploy@v0
         with:
           repoToken: '${{ secrets.GITHUB_TOKEN }}'

.gitignore

@@ -7,3 +7,4 @@ tmp
 .firebase
 app/libraries
 npm-debug.log
+dist/

firebase.json

@@ -1,7 +1,7 @@
 {
   "hosting": {
     "target": "speedtest",
-    "public": "app",
+    "public": "dist",
     "ignore": [
       "firebase.json",
       "**/.*",