feat: migrate from npm to bun and fix analytics map height

Switch package manager and runtime from Node.js/npm to Bun across
Docker, CI, and scripts. The SQLite driver remains better-sqlite3
due to Next.js Turbopack being unable to resolve bun:sqlite during
build-time page pre-rendering.

Also fix the world map not rendering in the analytics page — the
overflowX wrapper added for mobile broke the flex height chain,
collapsing the map to 0px.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/test.yml

@@ -22,14 +22,13 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v6
 
-      - name: Set up Node.js
-        uses: actions/setup-node@v6
+      - name: Set up Bun
+        uses: oven-sh/setup-bun@v2
         with:
-          node-version: '22'
-          cache: 'npm'
+          bun-version: latest
 
       - name: Install dependencies
-        run: npm ci
+        run: bun install --frozen-lockfile
 
       - name: Run unit and integration tests
-        run: npm test
+        run: bun run test