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>

Dockerfile

@@ -13,9 +13,9 @@ COPY tsconfig*.json ./
 RUN --mount=type=cache,target=/root/.npm \
     echo '{}' > package.json && \
     npm install --no-save typescript@^5.8.3 @types/node@^22.15.30 @types/express@^5.0.3 \
-        @modelcontextprotocol/sdk@^1.12.1 dotenv@^16.5.0 express@^5.1.0 axios@^1.10.0 \
+        @modelcontextprotocol/sdk@1.20.1 dotenv@^16.5.0 express@^5.1.0 axios@^1.10.0 \
         n8n-workflow@^1.96.0 uuid@^11.0.5 @types/uuid@^10.0.0 \
-        openai@^4.77.0 zod@^3.24.1 lru-cache@^11.2.1 @supabase/supabase-js@^2.57.4
+        openai@^4.77.0 zod@3.24.1 lru-cache@^11.2.1 @supabase/supabase-js@^2.57.4
 
 # Copy source and build
 COPY src ./src