Add GitHub workflows, release scripts, PR template

Add CI/CD and release automation assets: new GitHub Actions workflows (backend-foundation, hotfix-branch-creation, mobile-ci, product-release, web-quality), shell scripts for version/tag/release-note extraction and release-summary generation (.github/scripts/*), and a Pull Request template. Implements hotfix branch creation from tags, automatic tag name generation, version extraction from pubspec.yaml, CHANGELOG-based release notes extraction, selective mobile CI (detects changed files, builds and lints only affected Dart files), backend service test dry-runs, and automated GitHub release creation with summaries.

.github/workflows/web-quality.yml

@@ -0,0 +1,59 @@
+name: Web Quality
+
+on:
+  pull_request:
+    branches:
+      - dev
+      - main
+  push:
+    branches:
+      - dev
+      - main
+
+jobs:
+  web-quality:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: apps/web
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+          run_install: false
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: pnpm
+          cache-dependency-path: apps/web/pnpm-lock.yaml
+
+      - name: Setup Firebase CLI
+        working-directory: .
+        run: npm install -g firebase-tools
+
+      - name: Generate Data Connect SDK
+        working-directory: .
+        run: |
+          cp backend/dataconnect/dataconnect.dev.yaml backend/dataconnect/dataconnect.yaml
+          firebase dataconnect:sdk:generate --non-interactive
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Lint
+        run: pnpm lint
+
+      - name: Typecheck
+        run: pnpm typecheck
+
+      - name: Test
+        run: pnpm test
+
+      - name: Build
+        run: pnpm build