ci: image caching, Trivy scans, edge publishing, standalone installer

- docker-build job is now a per-app matrix with GHA layer cache, a
  container contents smoke check, and a non-blocking Trivy scan.
- New docker-publish job pushes edge + sha tags to GHCR on master.
- Fixed release.yml tagging ghcr.io/<Owner>/... with a mixed-case
  owner — GHCR requires lowercase, so tagged releases would have
  failed at push time.
- compose files: image: keys name local builds after the GHCR repos.
- install.sh: curl|bash installer — fetches compose files, generates
  secrets, pulls prebuilt images (docker pull + up --no-build, since
  compose pull skips buildable services), falls back to a source
  tarball build when packages aren't public.
- README: install section covering the one-liner, clone, and prebuilt
  paths plus common compose commands.

Verified locally: all three images build, full dev-overlay stack
passes scripts/smoke-e2e.sh, and install.sh produces a healthy
stack in a standalone directory.

Authored By: TDvorak <[email protected]>

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -6,6 +6,9 @@ on:
   pull_request:
     branches: [master]
 
+permissions:
+  contents: read
+
 jobs:
   backend-tests:
     name: Backend Tests
@@ -96,38 +99,83 @@ jobs:
         run: go build -v ./cmd/server
 
   docker-build:
-    name: Docker Build Test
+    name: Docker Build (${{ matrix.app }})
     runs-on: ubuntu-latest
-    
+    strategy:
+      fail-fast: false
+      matrix:
+        app: [backend, auth, frontend]
     steps:
       - uses: actions/checkout@v4
-      
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
-      
-      - name: Build backend image
+
+      - name: Build ${{ matrix.app }} image
         uses: docker/build-push-action@v6
         with:
           context: .
-          file: apps/backend/Dockerfile
+          file: apps/${{ matrix.app }}/Dockerfile
           push: false
-          tags: primora-backend:test
-      
-      - name: Build auth image
+          load: true
+          tags: primora-${{ matrix.app }}:test
+          cache-from: type=gha,scope=${{ matrix.app }}
+          cache-to: type=gha,mode=max,scope=${{ matrix.app }}
+
+      - name: Smoke check ${{ matrix.app }} image contents
+        run: |
+          case "${{ matrix.app }}" in
+            backend)  docker run --rm --entrypoint sh primora-backend:test -c 'test -x /usr/local/bin/primora-backend && test -x /usr/local/bin/dbx-mcp' ;;
+            auth)     docker run --rm --entrypoint sh primora-auth:test -c 'test -f /workspace/apps/auth/dist/index.js' ;;
+            frontend) docker run --rm --entrypoint sh primora-frontend:test -c 'test -f /usr/share/nginx/html/index.html' ;;
+          esac
+
+      - name: Scan ${{ matrix.app }} image
+        uses: aquasecurity/[email protected]
+        with:
+          image-ref: primora-${{ matrix.app }}:test
+          severity: CRITICAL,HIGH
+          ignore-unfixed: true
+          exit-code: '0'
+          format: table
+
+  docker-publish:
+    name: Publish edge images
+    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    needs: [docker-build, e2e-smoke]
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        app: [backend, auth, frontend]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-buildx-action@v3
+
+      # ghcr.io requires lowercase repo paths; the owner login may be mixed-case.
+      - name: Compute lowercase GHCR owner
+        run: echo "GHCR_OWNER=${GITHUB_REPOSITORY_OWNER,,}" >> "$GITHUB_ENV"
+
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Push edge + sha tags
         uses: docker/build-push-action@v6
         with:
           context: .
-          file: apps/auth/Dockerfile
-          push: false
-          tags: primora-auth:test
-      
-      - name: Build frontend image
-        uses: docker/build-push-action@v6
-        with:
-          context: .
-          file: apps/frontend/Dockerfile
-          push: false
-          tags: primora-frontend:test
+          file: apps/${{ matrix.app }}/Dockerfile
+          push: true
+          tags: |
+            ghcr.io/${{ env.GHCR_OWNER }}/primora-${{ matrix.app }}:edge
+            ghcr.io/${{ env.GHCR_OWNER }}/primora-${{ matrix.app }}:sha-${{ github.sha }}
+          cache-from: type=gha,scope=${{ matrix.app }}
+          cache-to: type=gha,mode=max,scope=${{ matrix.app }}
 
   migrations:
     name: Migration Up/Down
@@ -186,6 +234,12 @@ jobs:
       - name: Prepare env
         run: cp .env.example .env
 
+      - name: Validate compose files
+        run: >-
+          docker compose
+          -f docker-compose.yml -f docker-compose.dev.yml
+          config -q
+
       - name: Start stack
         run: >-
           docker compose