feat: Migrate app to TypeScript. Add Unit and UI tests

.github/workflows/ci.yml

@@ -0,0 +1,43 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build TypeScript
+        run: npm run build
+
+      - name: Run unit tests
+        run: npm test
+
+      - name: Install Playwright browsers
+        run: npx playwright install --with-deps chromium
+
+      - name: Run E2E tests
+        run: npm run test:e2e
+
+      - name: Upload Playwright report on failure
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: playwright-report
+          path: playwright-report/
+          retention-days: 7

.github/workflows/deploy.yml

@@ -0,0 +1,71 @@
+name: Deploy to GitHub Pages
+
+on:
+  workflow_run:
+    workflows:
+      - "Update Service Worker Cache Version"
+    types:
+      - completed
+    branches:
+      - main
+
+# Required for GitHub Pages deployment
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Only one Pages deployment at a time; do not cancel in-progress so we don't
+# leave the site in a half-deployed state.
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  deploy:
+    # Only deploy when the upstream workflow succeeded
+    if: ${{ github.event.workflow_run.conclusion == 'success' }}
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          # Use main explicitly so we pick up the bot-committed service worker
+          # cache version update that the upstream workflow may have just pushed.
+          ref: main
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build TypeScript
+        run: npm run build
+
+      - name: Stage PWA files for deployment
+        run: |
+          mkdir -p dist
+          cp index.html manifest.json service-worker.js dist/
+          cp icon-192.png icon-512.png dist/
+          cp -r css dist/
+          cp -r js dist/
+
+      - name: Configure GitHub Pages
+        uses: actions/configure-pages@v5
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist/
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

.gitignore

@@ -0,0 +1,14 @@
+# Dependencies
+node_modules/
+
+# TypeScript build output
+js/*.js
+js/*.js.map
+js/*.d.ts
+
+# Playwright
+test-results/
+playwright-report/
+
+# Misc
+.DS_Store

README.md

@@ -138,7 +138,64 @@ The app features a gamification system with points, levels, and daily streaks to
    - The app will appear in your applications menu
    - You can also launch it from the browser's apps page: `chrome://apps`
 
-## 🚀 Getting Started
+## �️ Development (TypeScript)
+
+This project is written in **TypeScript**. The source files live in `src/` and are compiled to `js/` for the browser.
+
+### Project Structure
+
+```
+src/              # TypeScript source files
+  storage.ts      # Data layer – StorageManager class & interfaces
+  app.ts          # UI layer – TaskManager class
+js/               # Compiled JavaScript (generated – do not edit)
+tests/            # Vitest unit tests
+e2e/              # Playwright end-to-end tests
+```
+
+### Prerequisites
+
+- [Node.js](https://nodejs.org/) (v18 or later recommended)
+
+### Setup
+
+```bash
+npm install                # Install dependencies
+npx playwright install     # Install Playwright browsers (first time only)
+```
+
+### Build
+
+```bash
+npm run build              # Compile TypeScript → js/
+npm run build:watch        # Compile in watch mode (auto-rebuild on save)
+```
+
+### Run Locally
+
+```bash
+npm run serve              # Start a local dev server at http://localhost:3000
+```
+
+### Testing
+
+```bash
+npm test                   # Run unit tests (Vitest)
+npm run test:watch         # Run unit tests in watch mode
+npm run test:e2e           # Run end-to-end tests (Playwright)
+npm run test:e2e:ui        # Run E2E tests with the Playwright UI
+```
+
+### Workflow
+
+1. Edit TypeScript files in `src/`.
+2. Run `npm run build` (or `build:watch`) to compile.
+3. Open the app via `npm run serve` or the `index.html` file.
+4. Run `npm test` to verify unit tests and `npm run test:e2e` for browser tests.
+
+> **Note:** Never edit files in `js/` directly — they are overwritten on every build.
+
+## �🚀 Getting Started
 
 1. **First Launch**
    - The app will load with empty data