feat: Introduce @automaker/prompts package for AI prompt templates

Changes:
- Added a new package, @automaker/prompts, containing AI prompt templates for enhancing user-written task descriptions.
- Implemented four enhancement modes: improve, technical, simplify, and acceptance, each with corresponding system prompts and examples.
- Updated relevant packages to utilize the new prompts package, ensuring backward compatibility with existing imports.
- Enhanced documentation to include usage examples and integration details for the new prompts.

Benefits:
✅ Streamlined AI prompt management across the codebase
✅ Improved clarity and usability for AI-powered features
✅ Comprehensive documentation for developers

All tests passing.

apps/server/package.json

@@ -25,6 +25,7 @@
     "@automaker/git-utils": "^1.0.0",
     "@automaker/model-resolver": "^1.0.0",
     "@automaker/platform": "^1.0.0",
+    "@automaker/prompts": "^1.0.0",
     "@automaker/types": "^1.0.0",
     "@automaker/utils": "^1.0.0",
     "cors": "^2.8.5",