refactor(factory): add pattern caching and type safety to validation

Improvements:
- Add ProviderMismatch TypedDict for type-safe return values
- Cache compiled regex patterns for better performance
- Update documentation to reflect optimizations

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

docs/architecture/orchestrator-validation.md

@@ -8,7 +8,8 @@ Scope: LLMRunner configuration validation and error classification
 
 **2026-04-16**: Refactored provider validation to centralize patterns in `factory.py`
 - Moved `_PROVIDER_BASE_URL_PATTERNS` from `llm_runner.py` to `ProviderSpec.base_url_patterns` in `factory.py`
-- Added `validate_provider_base_url()` function in factory for reusable validation
+- Added `validate_provider_base_url()` function with pattern caching for performance
+- Added `ProviderMismatch` TypedDict for type-safe validation results
 - Split ollama and openrouter into separate `ProviderSpec` entries (previously shared openai's spec)
 - Reduced `llm_runner.py` from 45 lines to 13 lines for validation logic
 - All 21 tests pass, including 6 provider mismatch tests

tradingagents/llm_clients/factory.py

@@ -1,5 +1,5 @@
 from dataclasses import dataclass
-from typing import Callable, Optional
+from typing import Callable, Optional, TypedDict
 import re
 
 from .base_client import BaseLLMClient
@@ -13,6 +13,16 @@ _OPENAI_COMPATIBLE = (
     "openai", "xai", "deepseek", "qwen", "glm", "ollama", "openrouter",
 )
 
+# Compiled pattern cache for validation performance
+_COMPILED_PATTERNS: dict[str, list[re.Pattern]] = {}
+
+
+class ProviderMismatch(TypedDict):
+    """Provider validation mismatch details."""
+    provider: str
+    backend_url: str
+    expected_patterns: tuple[str, ...]
+
 
 @dataclass(frozen=True)
 class ProviderSpec:
@@ -130,7 +140,7 @@ def create_llm_client(
     return provider_spec.builder(model, base_url, **kwargs)
 
 
-def validate_provider_base_url(provider: str, base_url: str) -> Optional[dict]:
+def validate_provider_base_url(provider: str, base_url: str) -> Optional[ProviderMismatch]:
     """Validate provider × base_url compatibility.
 
     Args:
@@ -138,12 +148,7 @@ def validate_provider_base_url(provider: str, base_url: str) -> Optional[dict]:
         base_url: API endpoint URL
 
     Returns:
-        None if valid, or dict with mismatch details if invalid:
-        {
-            "provider": str,
-            "backend_url": str,
-            "expected_patterns": tuple[str, ...]
-        }
+        None if valid, or ProviderMismatch dict if invalid
     """
     if not provider or not base_url:
         return None
@@ -161,9 +166,12 @@ def validate_provider_base_url(provider: str, base_url: str) -> Optional[dict]:
         # No validation rules defined for this provider
         return None
 
-    # Compile and test patterns
-    for pattern_str in spec.base_url_patterns:
-        pattern = re.compile(pattern_str)
+    # Use cached compiled patterns for performance
+    cache_key = spec.canonical_name
+    if cache_key not in _COMPILED_PATTERNS:
+        _COMPILED_PATTERNS[cache_key] = [re.compile(p) for p in spec.base_url_patterns]
+
+    for pattern in _COMPILED_PATTERNS[cache_key]:
         if pattern.search(base_url_lower):
             return None  # Match found