Fix Docker builds: missing deps + bump actions

Dockerfiles:
- Add db package.json to deps stage
- Copy full node_modules (including app-level) to runtime
- Copy packages/ dir for workspace imports at runtime

CD workflow:
- docker/login-action v3 → v4
- docker/build-push-action v6 → v7

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

.github/workflows/cd.yml

@@ -21,13 +21,13 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - uses: docker/login-action@v3
+      - uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - uses: docker/build-push-action@v6
+      - uses: docker/build-push-action@v7
         with:
           context: .
           file: apps/${{ matrix.app }}/Dockerfile
@@ -45,13 +45,13 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - uses: docker/login-action@v3
+      - uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - uses: docker/build-push-action@v6
+      - uses: docker/build-push-action@v7
         with:
           context: docker/brouter
           push: true