chore: prune unused imports and duplicate import redefinitions

Remove unused imports (F401) and duplicate/shadowed import
redefinitions (F811) across the codebase using ruff's safe
autofixes. No behavioral changes -- imports only.

- ~1400 safe autofixes applied across 644 files (net -1072 lines)
- __init__.py re-exports preserved (excluded from F401 removal so
  public re-export surfaces stay intact)
- Re-exports that are imported or monkeypatched by tests but look
  unused in their defining module are kept with explicit # noqa:
  F401 (gateway/run.py load_dotenv; run_agent re-exports from
  agent.message_sanitization, agent.context_compressor,
  agent.retry_utils, agent.prompt_builder, agent.process_bootstrap,
  agent.codex_responses_adapter)
- Unsafe F841 (unused-variable) fixes deliberately skipped -- those
  can change behavior when the RHS has side effects
- ruff lints remain disabled in pyproject.toml (only PLW1514 is
  selected); this is a one-time cleanup, not a config change

Verification:
- python -m compileall: clean
- pytest --collect-only: all 27161 tests collect (zero import errors)
- core entry points import clean (run_agent, model_tools, cli,
  toolsets, hermes_state, batch_runner, gateway)
- static scan: every name any test imports directly from an edited
  module still resolves

tools/browser_cdp_tool.py

@@ -257,7 +257,6 @@ def _browser_cdp_via_supervisor(
         )
 
     # Dispatch onto the supervisor's loop.
-    import asyncio as _asyncio
     loop = supervisor._loop  # type: ignore[attr-defined]
     if loop is None or not loop.is_running():
         return tool_error(

tools/browser_tool.py

@@ -55,7 +55,6 @@ import json
 import logging
 import os
 import re
-import signal
 import subprocess
 import shutil
 import sys

tools/code_execution_tool.py

@@ -35,7 +35,6 @@ import logging
 import os
 import platform
 import shlex
-import signal
 import socket
 import subprocess
 import sys

tools/computer_use/cua_backend.py

@@ -25,10 +25,8 @@ import os
 import platform
 import re
 import shutil
-import subprocess
 import sys
 import threading
-from concurrent.futures import Future
 from typing import Any, Dict, List, Optional, Tuple
 
 from tools.computer_use.backend import (

tools/cronjob_tools.py

@@ -7,7 +7,6 @@ Compatibility wrappers remain for direct Python callers and legacy tests.
 
 import json
 import logging
-import os
 import re
 import sys
 from pathlib import Path
@@ -23,7 +22,6 @@ sys.path.insert(0, str(Path(__file__).parent.parent))
 from cron.jobs import (
     AmbiguousJobReference,
     create_job,
-    get_job,
     list_jobs,
     parse_schedule,
     pause_job,

tools/environments/local.py

@@ -316,7 +316,7 @@ def _make_run_env(env: dict) -> dict:
     # Inject ContextVar-based session vars into subprocess env.
     # ContextVars don't propagate to child processes, so we bridge them here.
     try:
-        from gateway.session_context import get_session_env, _UNSET, _VAR_MAP
+        from gateway.session_context import _UNSET, _VAR_MAP
         for var_name, var in _VAR_MAP.items():
             value = var.get()
             if value is not _UNSET and value:

tools/memory_tool.py

@@ -26,7 +26,6 @@ Design:
 import json
 import logging
 import os
-import re
 import tempfile
 import time
 from contextlib import contextmanager

tools/send_message_tool.py

@@ -13,7 +13,6 @@ import re
 import ssl
 import time
 from email.utils import formatdate
-from typing import Dict, Optional
 
 from agent.redact import redact_sensitive_text
 
@@ -1270,7 +1269,6 @@ async def _send_email(extra, chat_id, message):
     """Send via SMTP (one-shot, no persistent connection needed)."""
     import smtplib
     from email.mime.text import MIMEText
-    from email.utils import formatdate
 
     address = extra.get("address") or os.getenv("EMAIL_ADDRESS", "")
     password = os.getenv("EMAIL_PASSWORD", "")

tools/skill_usage.py

@@ -31,7 +31,7 @@ import tempfile
 from contextlib import contextmanager
 from datetime import datetime, timezone
 from pathlib import Path
-from typing import Any, Dict, Iterable, List, Optional, Set, Tuple
+from typing import Any, Dict, List, Optional, Set, Tuple
 
 from hermes_constants import get_hermes_home
 from agent.skill_utils import is_excluded_skill_path

tools/web_tools.py

@@ -51,21 +51,9 @@ import httpx  # noqa: F401 — kept at module top so tests can patch tools.web_t
 if TYPE_CHECKING:
     from firecrawl import Firecrawl  # noqa: F401 — type hints only
 from plugins.web.firecrawl.provider import (
-    Firecrawl,
-    _FirecrawlProxy,
-    _FIRECRAWL_CLS_CACHE,
-    _extract_scrape_payload,
-    _extract_web_search_results,
     _firecrawl_backend_help_suffix,
-    _get_direct_firecrawl_config,
-    _get_firecrawl_client,
     _get_firecrawl_gateway_url,
-    _has_direct_firecrawl_config,
     _is_tool_gateway_ready,
-    _load_firecrawl_cls,
-    _normalize_result_list,
-    _raise_web_backend_configuration_error,
-    _to_plain_object,
     check_firecrawl_api_key,
 )
 # Tavily helpers re-exported for backward-compat with existing unit tests
@@ -112,7 +100,6 @@ from tools.tool_backend_helpers import (  # noqa: F401
     prefers_gateway,
 )
 from tools.url_safety import is_safe_url
-from tools.website_policy import check_website_access
 import sys
 
 logger = logging.getLogger(__name__)

tools/x_search_tool.py

@@ -44,7 +44,6 @@ from __future__ import annotations
 
 import json
 import logging
-import os
 import time
 from datetime import date, datetime, timezone
 from typing import Any, Dict, List, Optional, Tuple