refactor(agent/E_session): contextlib.suppress for swallow-only try/except

agent/session_activity.py

@@ -8,6 +8,7 @@ the default agent clock stamps ``unknown`` unless a writer passes an explicit ``
 from __future__ import annotations
 
 import time
+from contextlib import suppress
 from enum import Enum
 from typing import Any, Mapping, Optional
 
@@ -50,10 +51,8 @@ def normalize_activity_provenance(provenance: Optional[ActivityProvenance | str]
 def reset_session_activity_persist_window(agent: Any) -> None:
     """Clear the durable persist rate-limit so the next stamp writes through (terminal compression
     labels must not stay stuck on mid-compress text)."""
-    try:
+    with suppress(Exception):
         agent._session_activity_last_persist_mono = 0.0
-    except Exception:
-        pass
 
 
 def build_activity_snapshot(

agent/shell_hooks.py

@@ -20,7 +20,7 @@ import sys
 import tempfile
 import threading
 import time
-from contextlib import ExitStack, contextmanager
+from contextlib import ExitStack, contextmanager, suppress
 from dataclasses import dataclass, field
 from datetime import datetime, timezone
 from pathlib import Path
@@ -361,10 +361,8 @@ def _spawn(spec: ShellHookSpec, stdin_json: str) -> Dict[str, Any]:
     except Exception as exc:
         # Kill the whole tree — forked helpers holding the pipes would stall the drain.
         kill_process_tree(proc)
-        try:
+        with suppress(Exception):
             proc.communicate(timeout=1)
-        except Exception:
-            pass
         if not isinstance(exc, subprocess.TimeoutExpired):  # pragma: no cover — defensive
             return failed(str(exc))
         result["timed_out"] = True
@@ -540,10 +538,8 @@ def save_allowlist(data: Dict[str, Any]) -> None:
                 fh.write(json.dumps(data, indent=2, sort_keys=True))
             atomic_replace(tmp_path, p)
         except Exception:
-            try:
+            with suppress(OSError):
                 os.unlink(tmp_path)
-            except OSError:
-                pass
             raise
     except OSError as exc:
         logger.warning(
@@ -576,10 +572,8 @@ def _locked_update_approvals() -> Iterator[Dict[str, Any]]:
 
 
 def _flock_unlock(lock_fh: Any) -> None:
-    try:
+    with suppress(OSError):
         fcntl.flock(lock_fh.fileno(), fcntl.LOCK_UN)
-    except OSError:
-        pass
 
 
 def _prompt_and_record(event: str, command: str, *, accept_hooks: bool) -> bool:

agent/title_generator.py

@@ -11,6 +11,7 @@ import json
 import logging
 import re
 import threading
+from contextlib import suppress
 from typing import Any, Callable, Optional
 
 from agent.auxiliary_client import call_llm
@@ -407,10 +408,8 @@ def auto_title_session(
         from agent.portal_tags import set_conversation_context
 
         conversation_id = session_id
-        try:
+        with suppress(Exception):
             conversation_id = session_db.get_conversation_root(session_id) or session_id
-        except Exception:
-            pass
         set_conversation_context(conversation_id)
         set_accounting_context(session_db, session_id)
 

agent/trace_upload.py

@@ -14,6 +14,7 @@ import json
 import logging
 import os
 import uuid
+from contextlib import suppress
 from datetime import datetime, timezone
 from typing import Any, Dict, List, Optional, Tuple
 
@@ -225,11 +226,9 @@ def _do_upload(
 ) -> str:
     """Create (idempotently) the private dataset and push the trace file.
     Returns a user-facing status string. Never raises."""
-    try:
+    with suppress(Exception):  # lazy-install unavailable/declined — the import below surfaces the hint
         from tools import lazy_deps
         lazy_deps.ensure("tool.trace_upload", prompt=False)
-    except Exception:
-        pass  # lazy-install unavailable/declined — the import below surfaces the hint
     try:
         from huggingface_hub import HfApi
     except ImportError: