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>

docs/docker-fix-v2.6.2.md

@@ -0,0 +1,32 @@
+# Docker Fix for v2.6.2 - Missing Runtime Dependencies
+
+## Issue
+After v2.6.0, the Docker image started failing with:
+```
+Error: Cannot find module 'axios'
+```
+
+## Root Cause
+In v2.6.0, we added n8n management tools that require:
+- `axios` - For HTTP API calls to n8n instances
+- `zod` - For workflow validation schemas
+
+However, our ultra-optimized Docker image uses `package.runtime.json` which didn't include these new dependencies.
+
+## Fix
+Updated `package.runtime.json` to include:
+```json
+"axios": "^1.10.0",
+"zod": "^3.25.32"
+```
+
+## Impact
+- Docker image size increases slightly (~5MB) but remains much smaller than full n8n dependencies
+- No changes needed to Dockerfile itself - just the runtime package list
+- Users need to pull the latest Docker image after rebuild
+
+## Prevention
+When adding new features that require additional npm packages, always check:
+1. Is the package needed at runtime?
+2. If yes, add it to `package.runtime.json` for Docker builds
+3. Test the Docker image before release