feat: add dedicated testing agents and enhanced parallel orchestration

Introduce a new testing agent architecture that runs regression tests
independently from coding agents, improving quality assurance in
parallel mode.

Key changes:

Testing Agent System:
- Add testing_prompt.template.md for dedicated testing agent role
- Add feature_mark_failing MCP tool for regression detection
- Add --agent-type flag to select initializer/coding/testing mode
- Remove regression testing from coding prompt (now handled by testing agents)

Parallel Orchestrator Enhancements:
- Add testing agent spawning with configurable ratio (--testing-agent-ratio)
- Add comprehensive debug logging system (DebugLog class)
- Improve database session management to prevent stale reads
- Add engine.dispose() calls to refresh connections after subprocess commits
- Fix f-string linting issues (remove unnecessary f-prefixes)

UI Improvements:
- Add testing agent mascot (Chip) to AgentAvatar
- Enhance AgentCard to display testing agent status
- Add testing agent ratio slider in SettingsModal
- Update WebSocket handling for testing agent updates
- Improve ActivityFeed to show testing agent activity

API & Server Updates:
- Add testing_agent_ratio to settings schema and endpoints
- Update process manager to support testing agent type
- Enhance WebSocket messages for agent_update events

Template Changes:
- Delete coding_prompt_yolo.template.md (consolidated into main prompt)
- Update initializer_prompt.template.md with improved structure
- Streamline coding_prompt.template.md workflow

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

server/routers/settings.py

@@ -52,6 +52,23 @@ async def get_available_models():
     )
 
 
+def _parse_int(value: str | None, default: int) -> int:
+    """Parse integer setting with default fallback."""
+    if value is None:
+        return default
+    try:
+        return int(value)
+    except (ValueError, TypeError):
+        return default
+
+
+def _parse_bool(value: str | None, default: bool = False) -> bool:
+    """Parse boolean setting with default fallback."""
+    if value is None:
+        return default
+    return value.lower() == "true"
+
+
 @router.get("", response_model=SettingsResponse)
 async def get_settings():
     """Get current global settings."""
@@ -61,6 +78,8 @@ async def get_settings():
         yolo_mode=_parse_yolo_mode(all_settings.get("yolo_mode")),
         model=all_settings.get("model", DEFAULT_MODEL),
         glm_mode=_is_glm_mode(),
+        testing_agent_ratio=_parse_int(all_settings.get("testing_agent_ratio"), 1),
+        count_testing_in_concurrency=_parse_bool(all_settings.get("count_testing_in_concurrency")),
     )
 
 
@@ -73,10 +92,18 @@ async def update_settings(update: SettingsUpdate):
     if update.model is not None:
         set_setting("model", update.model)
 
+    if update.testing_agent_ratio is not None:
+        set_setting("testing_agent_ratio", str(update.testing_agent_ratio))
+
+    if update.count_testing_in_concurrency is not None:
+        set_setting("count_testing_in_concurrency", "true" if update.count_testing_in_concurrency else "false")
+
     # Return updated settings
     all_settings = get_all_settings()
     return SettingsResponse(
         yolo_mode=_parse_yolo_mode(all_settings.get("yolo_mode")),
         model=all_settings.get("model", DEFAULT_MODEL),
         glm_mode=_is_glm_mode(),
+        testing_agent_ratio=_parse_int(all_settings.get("testing_agent_ratio"), 1),
+        count_testing_in_concurrency=_parse_bool(all_settings.get("count_testing_in_concurrency")),
     )