Build canary image tags on branch pushes

.github/workflows/docker.yml

@@ -2,7 +2,13 @@ name: Build and Push Docker Image
 
 on:
   push:
-    branches: [main]
+    branches:
+      - main
+      - "codex/**"
+  pull_request:
+    branches:
+      - main
+  workflow_dispatch:
 
 jobs:
   build-and-push:
@@ -15,7 +21,22 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/domfelipe/hermes-agent-custom
+          tags: |
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=ref,event=branch
+            type=ref,event=pr
+            type=sha
+
       - name: Login to GitHub Container Registry
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
@@ -26,5 +47,6 @@ jobs:
         uses: docker/build-push-action@v5
         with:
           context: .
-          push: true
+          push: ${{ github.event_name != 'pull_request' }}
-          tags: ghcr.io/domfelipe/hermes-agent-custom:latest
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}