Add Claude-Sonnet-4-6 model support to frontend (#13224)

Co-authored-by: openhands <openhands@all-hands.dev>

openhands/llm/model_features.py

@@ -117,6 +117,7 @@ REASONING_EFFORT_PATTERNS: list[str] = [
     # DeepSeek reasoning family
     'deepseek-r1-0528*',
     'claude-sonnet-4-5*',
+    'claude-sonnet-4-6*',
     'claude-haiku-4-5*',
     # GLM series - verified via litellm config
     'glm-4*',

openhands/utils/llm.py

@@ -16,6 +16,7 @@ from openhands.llm import bedrock
 OPENHANDS_MODELS = [
     'openhands/claude-opus-4-6',
     'openhands/claude-opus-4-5-20251101',
+    'openhands/claude-sonnet-4-6',
     'openhands/claude-sonnet-4-5-20250929',
     'openhands/gpt-5.2-codex',
     'openhands/gpt-5.2',