fix: use root Containerfile (MCP bridge) for CI container builds

The container/ Containerfile requires a pre-built V binary that isn't
available in CI. The root Containerfile builds the lightweight MCP
stdio bridge which has zero dependencies and works in CI.

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

Author: hyperpolymath

.github/workflows/container-publish.yml

@@ -50,7 +50,7 @@ jobs:
         uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6.15.0
         with:
           context: .
-          file: container/Containerfile
+          file: Containerfile
           push: true
           tags: |
             ghcr.io/${{ github.repository }}:${{ steps.meta.outputs.version }}