fix: increase API read timeout from 90s to 300s to prevent flaky E2E failures

The flat 90s timeout was too aggressive for LLM-powered endpoints
(/testgen, /optimize, /refinement) under load, causing ReadTimeoutError
and failing the async-optimization E2E test. Split into (10s connect,
300s read) tuple so connections fail fast but LLM inference gets adequate time.

Author: KRRT7

codeflash/api/aiservice.py

@@ -47,7 +47,9 @@ def __init__(self) -> None:
         self.headers = {"Authorization": f"Bearer {get_codeflash_api_key()}", "Connection": "close"}
         self.llm_call_counter = count(1)
         self.is_local = self.base_url == "http://localhost:8000"
-        self.timeout: float | None = 300 if self.is_local else 90
+        # (connect_timeout, read_timeout) — connect should be fast; read
+        # can be slow because the server runs LLM inference.
+        self.timeout: float | tuple[float, float] | None = (10, 300)
 
     def get_next_sequence(self) -> int:
         """Get the next LLM call sequence number."""
@@ -88,7 +90,7 @@ def make_ai_service_request(
         endpoint: str,
         method: str = "POST",
         payload: dict[str, Any] | list[dict[str, Any]] | None = None,
-        timeout: float | None = None,
+        timeout: float | tuple[float, float] | None = None,
     ) -> requests.Response:
         """Make an API request to the given endpoint on the AI service.