🔗 Auto-register apps: Universal index discovery (#64)

* feat: Enhance CLI with improved list and smart remove commands

## ✨ New Features

### 🏠 Enhanced `leann list` command
- **Better UX**: Current project shown first with clear separation
- **Visual improvements**: Icons (🏠/📂), better formatting, size info
- **Smart guidance**: Context-aware usage examples and getting started tips

### 🛡️ Smart `leann remove` command
- **Safety first**: Always shows ALL matching indexes across projects
- **Intelligent handling**:
  - Single match: Clear location display with cross-project warnings
  - Multiple matches: Interactive selection with final confirmation
- **Prevents accidents**: No more deleting wrong indexes due to name conflicts
- **User-friendly**: 'c' to cancel, clear visual hierarchy, detailed info

### 🔧 Technical improvements
- **Clean logging**: Hide debug messages for better CLI experience
- **Comprehensive search**: Always scan all projects for transparency
- **Error handling**: Graceful handling of edge cases and user input

## 🎯 Impact
- **Safer**: Eliminates risk of accidental index deletion
- **Clearer**: Users always know what they're operating on
- **Smarter**: Automatic detection and handling of common scenarios

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

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

* chore: vscode ruff, and format

---------

Co-authored-by: Claude <noreply@anthropic.com>

apps/base_rag_example.py

@@ -10,6 +10,7 @@ from typing import Any
 
 import dotenv
 from leann.api import LeannBuilder, LeannChat
+from leann.registry import register_project_directory
 from llama_index.core.node_parser import SentenceSplitter
 
 dotenv.load_dotenv()
@@ -214,6 +215,11 @@ class BaseRAGExample(ABC):
         builder.build_index(index_path)
         print(f"Index saved to: {index_path}")
 
+        # Register project directory so leann list can discover this index
+        # The index is saved as args.index_dir/index_name.leann
+        # We want to register the current working directory where the app is run
+        register_project_directory(Path.cwd())
+
         return index_path
 
     async def run_interactive_chat(self, args, index_path: str):