fix(agent): corrupt-session recovery guidance names the session's own state.db

The corruption explainer filled `{db_path}` from `_default_db_path()`, the
process default. A Desktop `serve` backend launched on the root home hosts
named-profile sessions whose SessionDB is `profiles/<name>/state.db`, so the
operator was told to inspect/repair a different profile's database. Pass the
agent's own `_session_db.db_path` from the turn finalizer; the process
default remains the fallback for agents without a bound store.

Reported in #105887.

agent/turn_explainers.py

@@ -296,7 +296,7 @@ class TurnExplainersMixin:
 
     @staticmethod
     def _format_turn_completion_explanation(
-        turn_exit_reason: str, persistence_cause: Optional[str] = None
+        turn_exit_reason: str, persistence_cause: Optional[str] = None, db_path=None
     ) -> str:
         """User-facing explanation for an abnormal turn ending, or "" for normal / unknown reasons.
 
@@ -319,11 +319,14 @@ class TurnExplainersMixin:
                 persistence_cause or "unknown", _PERSISTENCE_DEFAULT_EXPLANATION
             )
             if persistence_cause == "corrupt":
-                # Copy-pasteable, so name the real store (profiles / HERMES_HOME do not live under ~/.hermes).
+                # Copy-pasteable, so name the store that actually failed: the agent's own
+                # SessionDB. A multi-profile backend (Desktop serve) hosts sessions whose
+                # state.db is NOT the process default, so the default would send the operator
+                # to inspect/repair the wrong profile's database (#105887).
                 from hermes_constants import get_default_hermes_root
                 from hermes_state import _default_db_path
 
-                body = body.replace("{db_path}", str(_default_db_path()))
+                body = body.replace("{db_path}", str(db_path or _default_db_path()))
                 body = body.replace(
                     "{backups_dir}", str(get_default_hermes_root() / "backups")
                 )

agent/turn_finalizer.py

@@ -375,7 +375,8 @@ def _explain_abnormal_exit(agent, final_response, _turn_exit_reason, preserved_v
         )
         if _is_empty_terminal or _is_partial_fragment or str(_turn_exit_reason) == "partial_stream_recovery":
             _explanation = agent._format_turn_completion_explanation(
-                _turn_exit_reason, getattr(agent, "_last_persistence_error_cause", None)
+                _turn_exit_reason, getattr(agent, "_last_persistence_error_cause", None),
+                db_path=getattr(getattr(agent, "_session_db", None), "db_path", None),
             )
             if _explanation:
                 # Replace the bare sentinel; keep a partial fragment and append why.

tests/run_agent/test_corruption_recovery_guidance.py

@@ -63,6 +63,26 @@ def test_gateway_corruption_banner_backups_dir_follows_hermes_home(monkeypatch,
     assert "~/.hermes/backups" not in sent[0]
 
 
+def test_format_turn_completion_corrupt_names_the_sessions_own_store(monkeypatch, tmp_path):
+    """Recovery commands target the store that failed, not the process default (#105887).
+
+    A Desktop ``serve`` backend launched on the root home hosts named-profile sessions
+    whose SessionDB is ``profiles/<name>/state.db``; guidance built from the process
+    default would tell the operator to inspect/repair the root database.
+    """
+    from run_agent import AIAgent
+
+    root = tmp_path / "root"
+    monkeypatch.setenv("HERMES_HOME", str(root))
+    failing = root / "profiles" / "research" / "state.db"
+
+    explanation = AIAgent._format_turn_completion_explanation(
+        "session_persistence_failed", "corrupt", db_path=failing
+    )
+    assert f"--source {failing} --inspect-only" in explanation
+    assert f"--source {root / 'state.db'}" not in explanation
+
+
 def test_format_turn_completion_corrupt_never_names_the_live_db():
     """The 'corrupt' cause must not direct a raw sqlite3 shell at the live DB.