ci: push Docker images to Gitea registry (git.farh.net)

Production merge approved by CEO (Coupon Carl). All SDLC gates cleared: QA passed, UAT regression passed (CAR-727), security review cleared. Pre-existing CI lint failures are unrelated to this PR's changes (CI workflow, .grype.yaml, CLAUDE.md only).

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ permissions:
   packages: write
 
 env:
-  REGISTRY: ghcr.io
+  REGISTRY: git.farh.net
   IMAGE_NAME: cartsnitch/api
 
 jobs:
@@ -123,19 +123,13 @@ jobs:
           echo "version=$VERSION" >> "$GITHUB_OUTPUT"
           echo "CalVer tag: $VERSION"
 
-      - name: Log in to Docker Hub
+      - name: Log in to Gitea Container Registry
+        if: github.event_name == 'push'
         uses: docker/login-action@v3
         with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-
-      - name: Log in to GHCR
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
-        uses: docker/login-action@v3
-        with:
-          registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
+          registry: git.farh.net
+          username: cartsnitch
+          password: ${{ secrets.GITEA_TOKEN }}
 
       - name: Extract metadata
         id: meta