fix(handoff): bound escalation assessment latency

Co-Authored-By: Codex <noreply@openai.com>

backend/app/core/config.py

@@ -111,6 +111,7 @@ class Settings(BaseSettings):
     GOOGLE_AI_API_KEY: Optional[str] = None
     AI_MODEL_GEMINI: str = "gemini-2.5-flash"
     AI_MODEL_ANTHROPIC: str = "claude-sonnet-4-6"
+    ESCALATION_AI_ASSESSMENT_TIMEOUT_SECONDS: int = 5
 
     # Model tier routing — maps action types to model tiers
     AI_MODEL_TIERS: dict[str, str] = {