Remove OpenAPI integration and simplify to manual tools only

- Remove all OpenAPI/Swagger integration code
- Simplify server to use only manual tools and resources
- Clean up unused imports (asyncio, pathlib, typing.Any/Dict)
- Remove complex fallback logic and OpenAPI validation
- Keep comprehensive 29 tools + 13 resources for full API coverage
- Maintain security automation tools (auto_configure_domain_security, analyze_domain_security)
- Version bump to 0.4.0 for major simplification

Benefits:
- Cleaner, more maintainable code
- No Swagger 2.0 vs OpenAPI 3.x compatibility issues
- Better error handling and reliability
- Reduced complexity while maintaining full functionality

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

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

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "mcp-mailu"
-version = "0.3.2"
+version = "0.4.0"
 description = "FastMCP server for Mailu email server API integration"
 authors = [
     {name = "Ryan Malloy", email = "ryan@supported.systems"}

uv.lock

@@ -613,7 +613,7 @@ wheels = [
 
 [[package]]
 name = "mcp-mailu"
-version = "0.3.1"
+version = "0.3.2"
 source = { editable = "." }
 dependencies = [
     { name = "fastmcp" },