Implement project picker keyboard shortcut and enhance feature management

- Added a new keyboard shortcut 'P' to open the project picker dropdown.
- Implemented functionality to select projects using number keys, allowing users to quickly switch between projects.
- Updated the feature list to include a new feature for project selection via keyboard shortcuts.
- Removed obsolete coding_prompt.md and added initializer_prompt.md for better session management.
- Introduced context management for features, enabling reading, writing, and deleting context files.
- Updated package dependencies to include @radix-ui/react-checkbox for enhanced UI components.

This commit enhances user experience by streamlining project selection and improves the overall feature management process.

🤖 Generated with Claude Code

app/package.json

@@ -19,6 +19,7 @@
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/sortable": "^10.0.0",
     "@dnd-kit/utilities": "^3.2.2",
+    "@radix-ui/react-checkbox": "^1.3.3",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-dropdown-menu": "^2.1.16",
     "@radix-ui/react-label": "^2.1.8",