ci: add gitflow — dev/stage/main branches with CI workflows

- dev.yaml: build + local docker smoke test only (no push, no deploy)
- stage.yaml: build + push + deploy to marketing-stage + smoke test (stops here)
- deploy.yaml: add HTML placeholder touch step before docker build

Proper human gate between stage and prod: the stage→main merge decision.

.gitea/workflows/deploy.yaml

@@ -115,6 +115,11 @@ jobs:
           echo "image=${IMAGE}" >> "$GITHUB_OUTPUT"
           echo "Will build and push: ${IMAGE}"
 
+      - name: Touch HTML placeholder files
+        # El binary regenerates these at startup via fs_write. They must exist
+        # in the build context for Dockerfile COPY to succeed.
+        run: touch src/index.html src/about.html src/terms.html src/enterprise-terms.html
+
       - name: Build image (build-stage.sh)
         if: steps.changetype.outputs.asset_only != 'true'
         env: