Use Sonnet for agents (faster, cheaper); overridable via AGENT_MODEL

Author: dev-pd

backend/app/core/config.py

@@ -24,8 +24,9 @@ class Settings(BaseSettings):
     anthropic_api_key: str = ""
     serp_api_key: str = ""
 
-    # The LLM that drives both agents. Latest Opus by default.
-    agent_model: str = "claude-opus-4-8"
+    # The LLM that drives both agents. Sonnet: faster + cheaper than Opus, fine for
+    # this structured audit task. Override via AGENT_MODEL in .env.
+    agent_model: str = "claude-sonnet-4-6"
     agent_max_tokens: int = 4096
 
     # Idle seed loop: the scheduler automatically cycles the curated seed jobs to grow