Initial implementation of n8n MCP server

Implements Hybrid MCP Light pattern with:
- 5 curated tools: list_workflows, get_workflow, list_executions, get_execution, trigger_webhook
- API pass-through tool: n8n_api_call for complete coverage
- API reference resource: n8n://api-reference
- Dockerfile and CI workflow for Gitea container registry

.gitea/workflows/build.yaml

@@ -0,0 +1,30 @@
+name: Build and Push n8n MCP Docker Image
+
+on:
+  push:
+    branches:
+      - main
+      - master
+
+jobs:
+  build:
+    runs-on: docker
+    container:
+      image: catthehacker/ubuntu:act-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Login to Gitea Container Registry
+        uses: docker/login-action@v2
+        with:
+          registry: gitea.ext.ben.io
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.CR_PAT }}
+
+      - name: Build and Push
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          push: true
+          tags: gitea.ext.ben.io/${{ gitea.repository }}:latest