Add shared httpd + PHP-FPM-only container architecture

Separate Apache and PHP-FPM into distinct container roles to reduce
per-customer memory overhead on shared servers. Adds three new images:
- Dockerfile.fpm: PHP-FPM only (no Apache), listens on TCP port 9000
- Dockerfile.shared-httpd: Apache only (no PHP), with SSL and proxy_fcgi
- Existing Dockerfile unchanged for standalone mode

Key changes:
- detect-memory.sh: CONTAINER_ROLE env var (combined/fpm_only/httpd_only)
  controls the memory budget split
- create-php-config.sh: FPM_LISTEN env var for TCP port vs Unix socket,
  added /fpm-ping and /fpm-status health endpoints
- New entrypoints for each container role
- tune-mpm.sh for hot-adjusting Apache MPM settings
- shared-vhost-template.tpl with proxy_fcgi and SSL on port 443
- CI/CD builds all three image types in parallel

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

.gitea/workflows/build-push.yaml

@@ -38,3 +38,65 @@ jobs:
           tags: |
             repo.anhonesthost.net/cloud-hosting-platform/cac:php${{ matrix.phpver }}
             ${{ matrix.phpver == '85' && 'repo.anhonesthost.net/cloud-hosting-platform/cac:latest' || '' }}
+
+  Build-FPM-Images:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        phpver: [74, 80, 81, 82, 83, 84, 85]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Gitea
+        uses: docker/login-action@v3
+        with:
+          registry: repo.anhonesthost.net
+          username: ${{ secrets.CI_USER }}
+          password: ${{ secrets.CI_TOKEN }}
+
+      - name: Build and Push FPM Image
+        uses: docker/build-push-action@v6
+        with:
+          file: ./Dockerfile.fpm
+          platforms: linux/amd64
+          push: true
+          build-args: |
+            PHPVER=${{ matrix.phpver }}
+          tags: |
+            repo.anhonesthost.net/cloud-hosting-platform/cac-fpm:php${{ matrix.phpver }}
+            ${{ matrix.phpver == '85' && 'repo.anhonesthost.net/cloud-hosting-platform/cac-fpm:latest' || '' }}
+
+  Build-Shared-httpd:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Gitea
+        uses: docker/login-action@v3
+        with:
+          registry: repo.anhonesthost.net
+          username: ${{ secrets.CI_USER }}
+          password: ${{ secrets.CI_TOKEN }}
+
+      - name: Build and Push Shared httpd Image
+        uses: docker/build-push-action@v6
+        with:
+          file: ./Dockerfile.shared-httpd
+          platforms: linux/amd64
+          push: true
+          tags: |
+            repo.anhonesthost.net/cloud-hosting-platform/shared-httpd:latest