feat(python/omp-rpc): added effort-based model thinking config parsing

- Updated `ThinkingConfig` and related types to model effort-based thinking settings with optional defaults and routing metadata.
- Added a dedicated parser for `model.thinking` payloads to validate efforts and normalize new optional thinking fields.
- Extended protocol tests to verify effort-based thinking data is parsed correctly and unknown efforts are rejected.

python/omp-rpc/src/omp_rpc/__init__.py

@@ -50,6 +50,7 @@ from .protocol import (
     CompactionSummaryMessage,
     CustomMessage,
     DeveloperMessage,
+    Effort,
     ExtensionError,
     ExtensionUiRequest,
     FileMentionMessage,
@@ -114,6 +115,7 @@ __all__ = [
     "CompactionSummaryMessage",
     "CustomMessage",
     "DeveloperMessage",
+    "Effort",
     "ExtensionError",
     "ExtensionErrorListener",
     "ExtensionUiRequest",