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/notifications/push.py

@@ -12,9 +12,9 @@ import logging
 import platform
 import subprocess
 from collections import deque
+from collections.abc import Callable
 from dataclasses import dataclass, field
-from datetime import datetime, timezone
-from typing import Optional
+from datetime import UTC, datetime
 
 logger = logging.getLogger(__name__)
 
@@ -25,7 +25,7 @@ class Notification:
     title: str
     message: str
     category: str  # swarm | task | agent | system | payment
-    timestamp: str = field(default_factory=lambda: datetime.now(timezone.utc).isoformat())
+    timestamp: str = field(default_factory=lambda: datetime.now(UTC).isoformat())
     read: bool = False
 
 
@@ -86,7 +86,7 @@ class PushNotifier:
         except Exception as exc:
             logger.debug("Native notification failed: %s", exc)
 
-    def recent(self, limit: int = 20, category: Optional[str] = None) -> list[Notification]:
+    def recent(self, limit: int = 20, category: str | None = None) -> list[Notification]:
         """Get recent notifications, optionally filtered by category."""
         notifs = list(self._notifications)
         if category:
@@ -114,7 +114,7 @@ class PushNotifier:
     def clear(self) -> None:
         self._notifications.clear()
 
-    def add_listener(self, callback: "Callable[[Notification], None]") -> None:
+    def add_listener(self, callback: Callable[[Notification], None]) -> None:
         """Register a callback for real-time notification delivery."""
         self._listeners.append(callback)
 
@@ -139,7 +139,7 @@ async def notify_briefing_ready(briefing) -> None:
         logger.info("Briefing ready but no pending approvals — skipping native notification")
         return
 
-    message = f"Your morning briefing is ready. " f"{n_approvals} item(s) await your approval."
+    message = f"Your morning briefing is ready. {n_approvals} item(s) await your approval."
     notifier.notify(
         title="Morning Briefing Ready",
         message=message,