Increase main agent timeout to 30 minutes for long delegate tasks

Changed from 600s (10 min) to 1800s (30 min) to prevent main agent
from timing out before delegate tasks can complete.

Timeout hierarchy:
- SubAgent idle timeout: 300s (5 min) - no progress
- SubAgent total timeout: 900s (15 min) - hard cap
- Delegate task timeout: 900s (15 min) - thread timeout
- Main agent timeout: 1800s (30 min) - allows long operations

This ensures main agent waits long enough for:
- Single delegate tasks up to 15 min
- Multiple sequential delegate tasks
- Complex tasks with retries

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

llm_interface.py

@@ -252,7 +252,7 @@ class LLMInterface:
                 # Block with 10-minute timeout to prevent hangs
                 # Complex tasks (repo analysis, multi-step operations) can take 5-8 minutes
                 logger.info("[LLM] Waiting for Agent SDK response (timeout: 600s)...")
-                result = future.result(timeout=600)
+                result = future.result(timeout=1800)  # 30 min to allow long delegate tasks
                 logger.info("[LLM] Agent SDK response received successfully")
                 return result
             except TimeoutError:
@@ -263,7 +263,7 @@ class LLMInterface:
                 msg_count = getattr(self, '_last_message_count', 0)
                 tools_used = getattr(self, '_last_tool_names', [])
                 
-                error_parts = [f"Task timed out after 10 minutes ({msg_count} messages processed)"]
+                error_parts = [f"Task timed out after 30 minutes ({msg_count} messages processed)"]
                 
                 if tools_used:
                     unique = list(dict.fromkeys(tools_used))