fix: add WithHttpTransport() for HTTP mode and add k8s manifests

HTTP transport mode was missing the required WithHttpTransport() call,
causing MapMcp() to fail. Also adds Kubernetes manifests for deployment.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

k8s/secret.yaml

@@ -0,0 +1,9 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  name: paperless-mcp
+  labels:
+    app: paperless-mcp
+type: Opaque
+stringData:
+  PAPERLESS_BASE_URL: "https://docs.barrywalker.io"