fix: update model version in agent configurations

Updated the default model version from "anthropic/claude-sonnet-4-20250514" to "anthropic/claude-sonnet-4.6" across multiple files including AGENTS.md, batch_runner.py, mini_swe_runner.py, and run_agent.py for consistency and to reflect the latest model improvements.

AGENTS.md

@@ -98,7 +98,7 @@ The main agent is implemented in `run_agent.py`:
 class AIAgent:
     def __init__(
         self,
-        model: str = "anthropic/claude-sonnet-4",
+        model: str = "anthropic/claude-sonnet-4.6",
         api_key: str = None,
         base_url: str = "https://openrouter.ai/api/v1",
         max_iterations: int = 60,        # Max tool-calling loops

batch_runner.py

@@ -1112,7 +1112,7 @@ def main(
     batch_size: int = None,
     run_name: str = None,
     distribution: str = "default",
-    model: str = "anthropic/claude-sonnet-4-20250514",
+    model: str = "anthropic/claude-sonnet-4.6",
     api_key: str = None,
     base_url: str = "https://openrouter.ai/api/v1",
     max_turns: int = 10,

mini_swe_runner.py

@@ -149,7 +149,7 @@ class MiniSWERunner:
     
     def __init__(
         self,
-        model: str = "anthropic/claude-sonnet-4-20250514",
+        model: str = "anthropic/claude-sonnet-4.6",
         base_url: str = None,
         api_key: str = None,
         env_type: str = "local",

run_agent.py

@@ -4077,7 +4077,7 @@ def main(
 
     Args:
         query (str): Natural language query for the agent. Defaults to Python 3.13 example.
-        model (str): Model name to use (OpenRouter format: provider/model). Defaults to anthropic/claude-sonnet-4-20250514.
+        model (str): Model name to use (OpenRouter format: provider/model). Defaults to anthropic/claude-sonnet-4.6.
         api_key (str): API key for authentication. Uses OPENROUTER_API_KEY env var if not provided.
         base_url (str): Base URL for the model API. Defaults to https://openrouter.ai/api/v1
         max_turns (int): Maximum number of API call iterations. Defaults to 10.