feat(02-01): export LinkParser and IdempotencyChecker from package root

- Add LinkParser and ParsedLink to __init__.py exports
- Add IdempotencyChecker to __init__.py exports
- Update __all__ list with new public APIs
- All 23 tests passing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

kb_pipeline/__init__.py

@@ -23,6 +23,8 @@ from .errors import (
 )
 from .config import KBSettings, get_settings
 from .retry import retry_on_network_error
+from .link_parser import LinkParser, ParsedLink
+from .idempotency import IdempotencyChecker
 
 __all__ = [
     # Schemas
@@ -47,6 +49,11 @@ __all__ = [
     "get_settings",
     # Retry
     "retry_on_network_error",
+    # Link Parser
+    "LinkParser",
+    "ParsedLink",
+    # Idempotency
+    "IdempotencyChecker",
 ]
 
 __version__ = "0.1.0"