fix: pin MCP SDK version in Docker build files (v2.27.1) (#456)

* fix: pin MCP SDK version in Docker build files (#454)

The Docker image 2.27.0 was missing the Zod fix from #450 because:
- package.runtime.json had @modelcontextprotocol/sdk@^1.13.2
- Dockerfile builder had @modelcontextprotocol/sdk@^1.12.1

Both now use the pinned version 1.20.1 (no caret) to match package.json.
Also pinned zod@3.24.1 in Dockerfile for consistency.

Fixes #454

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

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

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

* chore: bump version to 2.27.1 and update CHANGELOG

- Version bump from 2.27.0 to 2.27.1
- Added CHANGELOG entry for #454 fix (Docker SDK version)
- Added missing CHANGELOG entry for 2.27.0 (n8n_deploy_template)

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

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

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

---------

Co-authored-by: Claude <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.27.0",
+  "version": "2.27.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",