chore(lint): auto-fix 253 of 283 ruff issues (F401, I001, E402, RUF100, UP037, SIM105)

Mass ruff auto-fix:
  - ruff check --fix: 109 issues fixed (F401 unused imports,
    I001 unsorted imports, UP037 quoted annotations, SIM105
    suppressible exception, RUF100 unused-noqa)
  - ruff check --fix --unsafe-fixes: 22 additional issues
  - ruff format: 70 files reformatted
  - Manual pass: fix 16 misplaced import httpx lines
  - Manual pass: fix remaining E402 (import-after-docstring)

Result: 283 errors -> 30 errors.

The remaining 30 are real issues that need manual review:
  5 F401 unused-import (likely auto-generated stubs)
  5 F821 undefined-name (real bugs in code that references
    redis/pydantic/LLMRegistry without imports)
  3 BLE001 (the compliance LLM fallback is intentional; the
    other two are real)
  3 RUF012 mutable-class-default
  3 SIM105, 3 SIM117, 2 E722, 2 E741
  1 B007, 1 B025, 1 E402, 1 RUF200 (pyproject.toml issue)

Tests: 436/437 pass (1 pre-existing SSE sandbox failure).
format check + import sort: now clean.
make ci: still gated on the 30 remaining real issues.
Follow-up: triage the 30 issues file-by-file.

automator.py

@@ -14,6 +14,7 @@ all user inputs validated before passing to Playwright.
 
 import asyncio
 import base64
+import contextlib
 import json
 import os
 import time
@@ -291,15 +292,11 @@ class PryAutomator:
         async with self._lock:
             if session_id in self.sessions:
                 session = self.sessions.pop(session_id)
-                try:
+                with contextlib.suppress(OSError):
                     await session.browser.close()
-                except OSError:
-                    pass
                 if os.path.exists(session.cookies_file):
-                    try:
+                    with contextlib.suppress(OSError):
                         os.remove(session.cookies_file)
-                    except OSError:
-                        pass
 
     def list_sessions(self) -> list[dict]:
         return [
@@ -317,9 +314,5 @@ class PryAutomator:
             stale = [sid for sid, s in self.sessions.items() if now - s.last_used > SESSION_MAX_AGE]
             for sid in stale:
                 session = self.sessions.pop(sid)
-                try:
+                with contextlib.suppress(OSError):
                     await session.browser.close()
-                except OSError:
-                    pass
-
-