ruff (#169)

* polish: streamline nav, extract inline styles, improve tablet UX

- Restructure desktop nav from 8+ flat links + overflow dropdown into
  5 grouped dropdowns (Core, Agents, Intel, System, More) matching
  the mobile menu structure to reduce decision fatigue
- Extract all inline styles from mission_control.html and base.html
  notification elements into mission-control.css with semantic classes
- Replace JS-built innerHTML with secure DOM construction in
  notification loader and chat history
- Add CONNECTING state to connection indicator (amber) instead of
  showing OFFLINE before WebSocket connects
- Add tablet breakpoint (1024px) with larger touch targets for
  Apple Pencil / stylus use and safe-area padding for iPad toolbar
- Add active-link highlighting in desktop dropdown menus
- Rename "Mission Control" page title to "System Overview" to
  disambiguate from the chat home page
- Add "Home — Timmy Time" page title to index.html

https://claude.ai/code/session_015uPUoKyYa8M2UAcyk5Gt6h

* fix(security): move auth-gate credentials to environment variables

Hardcoded username, password, and HMAC secret in auth-gate.py replaced
with os.environ lookups. Startup now refuses to run if any variable is
unset. Added AUTH_GATE_SECRET/USER/PASS to .env.example.

https://claude.ai/code/session_015uPUoKyYa8M2UAcyk5Gt6h

* refactor(tooling): migrate from black+isort+bandit to ruff

Replace three separate linting/formatting tools with a single ruff
invocation. Updates tox.ini (lint, format, pre-push, pre-commit envs),
.pre-commit-config.yaml, and CI workflow. Fixes all ruff errors
including unused imports, missing raise-from, and undefined names.
Ruff config maps existing bandit skips to equivalent S-rules.

https://claude.ai/code/session_015uPUoKyYa8M2UAcyk5Gt6h

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/infrastructure/models/registry.py

@@ -11,20 +11,17 @@ model roles (student, teacher, judge/PRM) run on dedicated resources.
 import logging
 import sqlite3
 import threading
-from dataclasses import dataclass, field
-from datetime import datetime, timezone
-from enum import Enum
+from dataclasses import dataclass
+from datetime import UTC, datetime
+from enum import StrEnum
 from pathlib import Path
-from typing import Optional
-
-from config import settings
 
 logger = logging.getLogger(__name__)
 
 DB_PATH = Path("data/swarm.db")
 
 
-class ModelFormat(str, Enum):
+class ModelFormat(StrEnum):
     """Supported model weight formats."""
 
     GGUF = "gguf"  # Ollama-compatible quantised weights
@@ -33,7 +30,7 @@ class ModelFormat(str, Enum):
     OLLAMA = "ollama"  # Already loaded in Ollama by name
 
 
-class ModelRole(str, Enum):
+class ModelRole(StrEnum):
     """Role a model can play in the system (OpenClaw-RL style)."""
 
     GENERAL = "general"  # Default agent inference
@@ -60,7 +57,7 @@ class CustomModel:
 
     def __post_init__(self):
         if not self.registered_at:
-            self.registered_at = datetime.now(timezone.utc).isoformat()
+            self.registered_at = datetime.now(UTC).isoformat()
 
 
 def _get_conn() -> sqlite3.Connection:
@@ -178,11 +175,11 @@ class ModelRegistry:
             logger.info("Unregistered model: %s", name)
             return True
 
-    def get(self, name: str) -> Optional[CustomModel]:
+    def get(self, name: str) -> CustomModel | None:
         """Look up a model by name."""
         return self._models.get(name)
 
-    def list_models(self, role: Optional[ModelRole] = None) -> list[CustomModel]:
+    def list_models(self, role: ModelRole | None = None) -> list[CustomModel]:
         """List all registered models, optionally filtered by role."""
         models = list(self._models.values())
         if role is not None:
@@ -212,7 +209,7 @@ class ModelRegistry:
         if model_name not in self._models:
             return False
         with self._lock:
-            now = datetime.now(timezone.utc).isoformat()
+            now = datetime.now(UTC).isoformat()
             conn = _get_conn()
             conn.execute(
                 """
@@ -243,7 +240,7 @@ class ModelRegistry:
             del self._agent_assignments[agent_id]
         return True
 
-    def get_agent_model(self, agent_id: str) -> Optional[CustomModel]:
+    def get_agent_model(self, agent_id: str) -> CustomModel | None:
         """Get the model assigned to an agent, or None for default."""
         model_name = self._agent_assignments.get(agent_id)
         if model_name:
@@ -256,13 +253,13 @@ class ModelRegistry:
 
     # ── Role-based lookups ─────────────────────────────────────────────────
 
-    def get_reward_model(self) -> Optional[CustomModel]:
+    def get_reward_model(self) -> CustomModel | None:
         """Get the active reward/PRM model, if any."""
         reward_models = self.list_models(role=ModelRole.REWARD)
         active = [m for m in reward_models if m.active]
         return active[0] if active else None
 
-    def get_teacher_model(self) -> Optional[CustomModel]:
+    def get_teacher_model(self) -> CustomModel | None:
         """Get the active teacher model for distillation."""
         teacher_models = self.list_models(role=ModelRole.TEACHER)
         active = [m for m in teacher_models if m.active]