docs(changelog): add entry for v0.5.0 release

Implement MCP server mode with new commands, tools, and configurations.
Add support for recipes and prompts, including unit tests and user guide.
Update README and handlers for enhanced MCP functionality.

CHANGELOG.md

@@ -1,3 +1,22 @@
+## [v0.5.0] - 2026-04-06
+
+MCP server mode arrives, ready to serve your AI coding whims.
+
+### Added
+- Implement `grokkit mcp` command for MCP server over stdio.
+- Add ListRecipes and ListAvailablePrompts functions.
+- Export analysis, docs, and testgen functions for MCP tools.
+- Add tools: lint_code, analyze_code, generate_docs, generate_tests, generate_commit_msg, run_recipe.
+- Register resources: recipes://local, recipes://global, prompts://language.
+- Add MCP config options and dependencies.
+- Add unit tests for analyze, docs, mcp, prompts, recipe, and testgen packages.
+- Add user guide for MCP.
+- Add detailed plan in todo/queued/mcp-feature.md.
+- Add MCP server mode to queued tasks in TODO README.
+
+### Changed
+- Update MCP server handlers for local/global recipes and prompts.
+- Update README with MCP details.
 ## [v0.4.0] - 2026-03-31
 
 Workon command arrives: because who needs manual todos when AI can branch out for you?