feat: Enhance CLI with improved list and smart remove commands (#63)

- **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

- **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

- **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

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

packages/leann-core/src/leann/registry.py

@@ -2,11 +2,15 @@
 
 import importlib
 import importlib.metadata
+import logging
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
     from leann.interface import LeannBackendFactoryInterface
 
+# Set up logger for this module
+logger = logging.getLogger(__name__)
+
 BACKEND_REGISTRY: dict[str, "LeannBackendFactoryInterface"] = {}
 
 
@@ -14,7 +18,7 @@ def register_backend(name: str):
     """A decorator to register a new backend class."""
 
     def decorator(cls):
-        print(f"INFO: Registering backend '{name}'")
+        logger.debug(f"Registering backend '{name}'")
         BACKEND_REGISTRY[name] = cls
         return cls