refactor(state): one canonical-path helper for holder scans

Follow-up on the #97330 salvage (#97329): main grew `_canonical_sqlite_path`
after the PR's base; the holder module re-implemented it as a closure. Export
`canonical_sqlite_path` from hermes_state_holders and alias the legacy name in
hermes_state. Drop the unused `_read_proc_argv` / `_looks_like_hermes`
re-exports (no in-tree callers).

hermes_state.py

@@ -4541,9 +4541,7 @@ def _stat_sqlite_sidecar_identity(db_path: Path) -> Dict[str, tuple]:
     return identities
 
 
-def _canonical_sqlite_path(path: str) -> str:
-    """Normalize a /proc fd target, stripping the Linux `` (deleted)`` suffix."""
-    return os.path.normcase(os.path.abspath(path.removesuffix(" (deleted)")))
+_canonical_sqlite_path = _state_holders.canonical_sqlite_path
 
 
 def _watched_sqlite_sidecar_paths(db_path) -> Set[str]:
@@ -5074,10 +5072,6 @@ def _concrete_state_db_holder_pids(
     return pids
 
 
-_read_proc_argv = _state_holders._read_proc_argv
-_looks_like_hermes = _state_holders._looks_like_hermes
-
-
 # Lifecycle statuses surfaced by session pickers. Classification looks ONLY at
 # a session's final message row — role, whether it carries tool_calls, and its
 # finish_reason — so it stays O(1) per session (see

hermes_state_holders.py

@@ -120,6 +120,11 @@ def _looks_like_hermes(argv: Sequence[str]) -> bool:
     )
 
 
+def canonical_sqlite_path(path: str) -> str:
+    """Normalize a /proc fd target, stripping the Linux `` (deleted)`` suffix."""
+    return os.path.normcase(os.path.abspath(path.removesuffix(" (deleted)")))
+
+
 def foreign_state_db_holders(db_path: Path) -> List[Tuple[int, str]]:
     """Return foreign holders of the DB or one of its WAL sidecars.
 
@@ -130,15 +135,11 @@ def foreign_state_db_holders(db_path: Path) -> List[Tuple[int, str]]:
     if _IS_WINDOWS:
         return []
 
-    def _canonical(path: str) -> str:
-        clean = path.removesuffix(" (deleted)")
-        return os.path.normcase(os.path.abspath(clean))
-
     db_path_str = os.path.abspath(os.fspath(db_path))
     watched = {
-        _canonical(db_path_str),
-        _canonical(db_path_str + "-wal"),
-        _canonical(db_path_str + "-shm"),
+        canonical_sqlite_path(db_path_str),
+        canonical_sqlite_path(db_path_str + "-wal"),
+        canonical_sqlite_path(db_path_str + "-shm"),
     }
     holders: List[Tuple[int, str]] = []
     watched_ids: Set[Tuple[int, int]] = set()
@@ -190,7 +191,7 @@ def foreign_state_db_holders(db_path: Path) -> List[Tuple[int, str]]:
                                 )
                             )
                         continue
-                    target_is_watched = _canonical(target) in watched
+                    target_is_watched = canonical_sqlite_path(target) in watched
                     try:
                         fd_stat = os.stat(fd_path)
                     except OSError as exc:
@@ -237,7 +238,7 @@ def foreign_state_db_holders(db_path: Path) -> List[Tuple[int, str]]:
                 continue
             for opened in info.get("open_files") or ():
                 path = getattr(opened, "path", "")
-                if path and _canonical(path) in watched:
+                if path and canonical_sqlite_path(path) in watched:
                     holders.append((pid, path))
     except Exception as exc:
         logger.warning(