fix(gateway): only stamp a session's own directory on its row

Two existing cases in tests/test_tui_gateway_server.py covered the row's cwd
contract and this change had to answer both.

`_persisted_session_cwd` reached through `_session_cwd`, which falls back to
the gateway-wide completion cwd when the session carries none. That belongs to
no session in particular, so a session that never had a directory was given
one. Read the session's own `cwd` instead.

The remaining case asserted that a terminal session's directory is discarded,
which is the behavior this branch deliberately changes. Split it in two: a
terminal session now records its workspace, and the desktop keeps the "No
workspace" default it was written to protect.

tests/test_tui_gateway_server.py

@@ -4066,9 +4066,13 @@ def test_ensure_session_db_row_persists_session_source(monkeypatch):
     ]
 
 
-def test_ensure_session_db_row_defaults_to_no_workspace(monkeypatch, tmp_path):
-    """Without an explicit workspace, cwd is left null so the session groups
-    under "No workspace" rather than the gateway's launch directory."""
+def test_ensure_session_db_row_records_a_terminal_workspace(monkeypatch, tmp_path):
+    """A terminal session's directory IS its workspace, so the row records it.
+
+    The user cd'd there before running hermes. Leaving it null stranded the row
+    with no cwd and no git_repo_root, so the sidebar could never place the
+    session under its project.
+    """
     created = []
 
     class _FakeDB:
@@ -4085,7 +4089,28 @@ def test_ensure_session_db_row_defaults_to_no_workspace(monkeypatch, tmp_path):
     server._ensure_session_db_row({"session_key": "k1", "cwd": str(tmp_path)})
 
     assert created == [
-        {"key": "k1", "source": "tui", "model": "test-model", "model_config": None, "cwd": None}
+        {"key": "k1", "source": "tui", "model": "test-model", "model_config": None, "cwd": str(tmp_path)}
+    ]
+
+
+def test_ensure_session_db_row_defaults_desktop_to_no_workspace(monkeypatch, tmp_path):
+    """The desktop launches from wherever the bundle was opened, so an unpicked
+    cwd is an artifact — those chats stay null and group under "No workspace"."""
+    created = []
+
+    class _FakeDB:
+        def create_session(self, key, source=None, model=None, model_config=None, parent_session_id=None, cwd=None, profile_name=None):
+            created.append(
+                {"key": key, "source": source, "model": model, "model_config": model_config, "cwd": cwd}
+            )
+
+    monkeypatch.setattr(server, "_get_db", lambda: _FakeDB())
+    monkeypatch.setattr(server, "_resolve_model", lambda: "test-model")
+
+    server._ensure_session_db_row({"session_key": "k1", "source": "desktop", "cwd": str(tmp_path)})
+
+    assert created == [
+        {"key": "k1", "source": "desktop", "model": "test-model", "model_config": None, "cwd": None}
     ]
 
 

tui_gateway/server.py

@@ -2102,7 +2102,10 @@ def _persisted_session_cwd(session: dict) -> str | None:
         return _session_cwd(session)
     if _session_source(session) in _LAUNCH_CWD_NOT_A_WORKSPACE:
         return None
-    return _session_cwd(session) or None
+    # Only the session's OWN directory. `_session_cwd` falls back to the
+    # gateway-wide completion cwd, which belongs to no session in particular —
+    # stamping that would invent a workspace for a session that never had one.
+    return str(session.get("cwd") or "") or None
 
 
 def _heal_dead_cwd(cwd: str) -> str: