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/timmy/memory_system.py

@@ -12,9 +12,8 @@ Handoff Protocol:
 
 import logging
 import re
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from pathlib import Path
-from typing import Optional
 
 logger = logging.getLogger(__name__)
 
@@ -30,8 +29,8 @@ class HotMemory:
 
     def __init__(self) -> None:
         self.path = HOT_MEMORY_PATH
-        self._content: Optional[str] = None
-        self._last_modified: Optional[float] = None
+        self._content: str | None = None
+        self._last_modified: float | None = None
 
     def read(self, force_refresh: bool = False) -> str:
         """Read hot memory, with caching."""
@@ -130,8 +129,8 @@ class HotMemory:
 
 *Prune date: {prune_date}*
 """.format(
-            date=datetime.now(timezone.utc).strftime("%Y-%m-%d"),
-            prune_date=(datetime.now(timezone.utc).replace(day=25)).strftime("%Y-%m-%d"),
+            date=datetime.now(UTC).strftime("%Y-%m-%d"),
+            prune_date=(datetime.now(UTC).replace(day=25)).strftime("%Y-%m-%d"),
         )
 
         self.path.write_text(default_content)
@@ -154,14 +153,14 @@ class VaultMemory:
     def write_note(self, name: str, content: str, namespace: str = "notes") -> Path:
         """Write a note to the vault."""
         # Add timestamp to filename
-        timestamp = datetime.now(timezone.utc).strftime("%Y%m%d")
+        timestamp = datetime.now(UTC).strftime("%Y%m%d")
         filename = f"{timestamp}_{name}.md"
         filepath = self.path / namespace / filename
 
         # Add header
         full_content = f"""# {name.replace("_", " ").title()}
 
-> Created: {datetime.now(timezone.utc).isoformat()}
+> Created: {datetime.now(UTC).isoformat()}
 > Namespace: {namespace}
 
 ---
@@ -190,7 +189,7 @@ class VaultMemory:
             return []
         return sorted(dir_path.glob(pattern))
 
-    def get_latest(self, namespace: str = "notes", pattern: str = "*.md") -> Optional[Path]:
+    def get_latest(self, namespace: str = "notes", pattern: str = "*.md") -> Path | None:
         """Get most recent file in namespace."""
         files = self.list_files(namespace, pattern)
         return files[-1] if files else None
@@ -219,7 +218,7 @@ class VaultMemory:
         # Update last_updated
         content = re.sub(
             r"\*Last updated:.*\*",
-            f"*Last updated: {datetime.now(timezone.utc).strftime('%Y-%m-%d')}*",
+            f"*Last updated: {datetime.now(UTC).strftime('%Y-%m-%d')}*",
             content,
         )
 
@@ -255,7 +254,7 @@ class VaultMemory:
 ---
 
 *Last updated: {date}*
-""".format(date=datetime.now(timezone.utc).strftime("%Y-%m-%d"))
+""".format(date=datetime.now(UTC).strftime("%Y-%m-%d"))
 
         profile_path.write_text(default)
 
@@ -277,7 +276,7 @@ class HandoffProtocol:
         """Write handoff at session end."""
         content = f"""# Last Session Handoff
 
-**Session End:** {datetime.now(timezone.utc).isoformat()}
+**Session End:** {datetime.now(UTC).isoformat()}
 **Duration:** (calculated on read)
 
 ## Summary
@@ -316,7 +315,7 @@ The user was last working on: {session_summary[:200]}...
             len(open_items),
         )
 
-    def read_handoff(self) -> Optional[str]:
+    def read_handoff(self) -> str | None:
         """Read handoff if exists."""
         if not self.path.exists():
             return None
@@ -336,13 +335,13 @@ class MemorySystem:
         self.hot = HotMemory()
         self.vault = VaultMemory()
         self.handoff = HandoffProtocol()
-        self.session_start_time: Optional[datetime] = None
+        self.session_start_time: datetime | None = None
         self.session_decisions: list[str] = []
         self.session_open_items: list[str] = []
 
     def start_session(self) -> str:
         """Start a new session, loading context from memory."""
-        self.session_start_time = datetime.now(timezone.utc)
+        self.session_start_time = datetime.now(UTC)
 
         # Build context
         context_parts = []
@@ -379,7 +378,7 @@ class MemorySystem:
         # Update hot memory
         self.hot.update_section(
             "Current Session",
-            f"**Last Session:** {datetime.now(timezone.utc).strftime('%Y-%m-%d %H:%M')}\n"
+            f"**Last Session:** {datetime.now(UTC).strftime('%Y-%m-%d %H:%M')}\n"
             + f"**Summary:** {summary[:100]}...",
         )