fix: add missing runtime dependencies for Docker image

- Add axios (^1.10.0) for n8n API client
- Add zod (^3.25.32) for workflow validation
- Update runtime package version to 2.6.2
- Update Dockerfile comment to reflect minimal (not zero) dependencies

Fixes Docker runtime error: "Cannot find module 'axios'"
introduced by n8n management tools in v2.6.0

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

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

package.runtime.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp-runtime",
-  "version": "2.4.1",
+  "version": "2.6.2",
   "description": "n8n MCP Server Runtime Dependencies Only",
   "private": true,
   "dependencies": {
@@ -8,7 +8,9 @@
     "better-sqlite3": "^11.10.0",
     "sql.js": "^1.13.0",
     "express": "^5.1.0",
-    "dotenv": "^16.5.0"
+    "dotenv": "^16.5.0",
+    "axios": "^1.10.0",
+    "zod": "^3.25.32"
   },
   "engines": {
     "node": ">=16.0.0"