feat(docker): add Streamable HTTP transport deployment with TDD unit tests

[gthieleb]

Summary

Enables Docker deployment of the Streamable HTTP transport with proper health checks, optional compose override pattern, and TDD unit tests for the HTTP handler.

What's New

HTTP Handler Extraction (src/http-handler.ts)

• Extracted HTTP handler logic from main.ts into createHttpHandler(deps) factory function
• Handles /health (GET), /mcp (POST) routing, and session management
• Minimal extraction — no behavioral changes to existing stdio transport

TDD Unit Tests (src/http-handler.test.ts)

• 8 unit tests covering: health endpoint, MCP routing, session management, error handling
• Uses vi.hoisted() + vi.mock() for clean SDK mocking
• All 158 existing tests + 8 new tests pass

Docker Improvements

• Both Dockerfile and Dockerfile.alpine now EXPOSE 8080 with HEALTHCHECK
• New docker-healthcheck.js — readable health check script (replaces cryptic oneliner)
• Port configurable via CLI argument: node docker-healthcheck.js 8080

Docker Compose: Optional HTTP Override Pattern

• Base docker-compose.yml → stdio only (default, unchanged behavior)
• docker-compose.override.example.yml → template for HTTP mode
• Users activate HTTP with: cp docker-compose.override.example.yml docker-compose.override.yml
• Override file is gitignored — user's local config, never committed

Documentation

• README updated with HTTP Docker deployment instructions
• Explains override pattern, health check, and configuration

Files Changed (12 files, +580 / -109)

File	Change
src/http-handler.ts	New — Extracted HTTP handler with createHttpHandler() factory
src/http-handler.test.ts	New — 8 TDD unit tests
src/main.ts	Simplified — imports extracted handler
src/services/hooks.service.ts	Minor — hooks start on client initialized (HTTP mode)
Dockerfile	Added EXPOSE, HEALTHCHECK via docker-healthcheck.js
Dockerfile.alpine	Same as slim variant
docker-healthcheck.js	New — Readable health check script
docker-compose.yml	Simplified — single service, stdio only
docker-compose.override.example.yml	New — HTTP override template
server.json	Added streamable-http transport package entry
README.md	HTTP Docker deployment docs
.gitignore	Added .sisyphus/ and docker-compose.override.yml

Testing

• pnpm test → 166 tests pass (158 existing + 8 new)
• Docker container: healthy, /health returns 200, MCP handshake verified
• Full MCP protocol tested: initialize → notifications/initialized → tools/list returns 47+ tools
• Tested on Tailscale/WireGuard interface (100.108.41.111:15002)

Breaking Changes

None. Default behavior (stdio transport) is unchanged.

Notes

• No new dependencies added
• No SSE transport implementation — Streamable HTTP only
• No auth, CORS, TLS, or reverse proxy configuration
• docker-compose.override.yml is gitignored by design (user-specific)

[gthieleb]

Reopened this PR against the more actively maintained fork: wgs4/email-mcp#16

No changes to the implementation — just rebased onto wgs4/main which includes additional bug fixes and features (attachment support, search improvements, cross-account move). All 389 tests pass.