feat: comprehensive test infrastructure improvements

- Fix unit test imports: add env setup in conftest.py before module imports
- Add 24 new auth router tests (RBAC, preferences, password validation)
- Add 16 new tests for litellm and chat_summary routers
- Apply black formatting and ruff linting across codebase
- Add pre-commit hooks configuration (black, ruff, file checks)
- Increase CI coverage threshold from 40% to 50%

Test Results:
- 206 tests passing (91 unit + 115 integration)
- Coverage: 58.79% on core modules
- auth.py: 57% → 85%, litellm.py: 23% → 87%, chat_summary.py: 41% → 100%
- auth_service: 96.51%, config: 100%, rbac: 93.48%

dashboard/backend/services/agents/base_agent.py

@@ -1,17 +1,18 @@
 """
 Base Agent Class - Foundation for all OPC agents
 """
-from typing import Dict, Any, List, Optional
+
 import json
-import httpx
 import os
-from datetime import datetime
+from typing import Any
+
+import httpx
 
 
 class BaseAgent:
     """Base class for all OPC agents"""
 
-    def __init__(self, agent_id: str, name: str, role: str, system_prompt: str, config: Dict[str, Any]):
+    def __init__(self, agent_id: str, name: str, role: str, system_prompt: str, config: dict[str, Any]):
         self.agent_id = agent_id
         self.name = name
         self.role = role
@@ -20,7 +21,7 @@ class BaseAgent:
         self.litellm_url = os.getenv("LITELLM_URL", "http://litellm:4005")
         self.litellm_api_key = os.getenv("LITELLM_API_KEY", "")
 
-    async def execute(self, task: Dict[str, Any], context: Dict[str, Any]) -> Dict[str, Any]:
+    async def execute(self, task: dict[str, Any], context: dict[str, Any]) -> dict[str, Any]:
         """
         Execute agent on a task
         Returns: {
@@ -40,7 +41,7 @@ class BaseAgent:
 
         return result
 
-    def _build_prompt(self, task: Dict[str, Any], context: Dict[str, Any]) -> str:
+    def _build_prompt(self, task: dict[str, Any], context: dict[str, Any]) -> str:
         """Build the prompt for the LLM"""
         prompt = f"""You are {self.name}, a {self.role} agent.
 
@@ -77,6 +78,7 @@ Only propose actions you can actually execute. Be specific and actionable."""
     async def _call_llm(self, prompt: str) -> str:
         """Call LiteLLM proxy"""
         import logging
+
         logger = logging.getLogger(__name__)
 
         model = self.config.get("model", "claude-sonnet-4-6")
@@ -96,11 +98,11 @@ Only propose actions you can actually execute. Be specific and actionable."""
                         "model": model,
                         "messages": [
                             {"role": "system", "content": self.system_prompt},
-                            {"role": "user", "content": prompt}
+                            {"role": "user", "content": prompt},
                         ],
                         "temperature": temperature,
-                        "max_tokens": 2000
-                    }
+                        "max_tokens": 2000,
+                    },
                 )
                 response.raise_for_status()
                 data = response.json()
@@ -118,7 +120,7 @@ Only propose actions you can actually execute. Be specific and actionable."""
             logger.error(f"LiteLLM call failed: {e}")
             raise Exception(f"LLM call failed: {str(e)}")
 
-    def _parse_response(self, response: str) -> Dict[str, Any]:
+    def _parse_response(self, response: str) -> dict[str, Any]:
         """Parse LLM response and extract actions"""
         try:
             # Try to extract JSON from response
@@ -148,16 +150,11 @@ Only propose actions you can actually execute. Be specific and actionable."""
             # Fallback: return error action
             return {
                 "reasoning": f"Failed to parse response: {str(e)}",
-                "actions": [
-                    {
-                        "type": "error",
-                        "message": f"Agent response parsing failed: {str(e)}"
-                    }
-                ],
-                "requires_approval": False
+                "actions": [{"type": "error", "message": f"Agent response parsing failed: {str(e)}"}],
+                "requires_approval": False,
             }
 
-    def get_capabilities(self) -> List[str]:
+    def get_capabilities(self) -> list[str]:
         """Get agent capabilities"""
         return self.config.get("capabilities", [])