Release v0.51.276 — Release IR (stage-p3e — preserve manually-named session titles #3542) (#3682)

* feat(sessions): skip adaptive auto-rename for manually-named sessions (#3542, #3230)

Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>

* docs(changelog): v0.51.276 — Release IR (stage-p3e)

* fix(sessions): clear manual_title lock on /api/session/clear (#3542)

Codex regression-gate follow-up: the clear endpoint reset the title to
Untitled directly, stranding manual_title=True so the reused session never
auto-named again. Route the reset through apply_session_title_rename (which
clears the lock for auto-labels) + add a behavioral and a static-guard test.

---------

Co-authored-by: nesquena-hermes <[email protected]>
Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>

api/session_ops.py

@@ -14,6 +14,36 @@ from api.models import get_session, SESSIONS
 
 logger = logging.getLogger(__name__)
 
+AUTO_TITLE_LABELS = {'untitled', 'new chat'}
+
+
+def session_has_manual_title(session) -> bool:
+    """Return whether adaptive title refresh should leave this title alone."""
+    return getattr(session, 'manual_title', False) is True
+
+
+def apply_session_title_rename(session, raw_title) -> str:
+    """Apply user-driven rename semantics to a Session object.
+
+    Non-empty custom titles are protected from adaptive refresh. Clearing the
+    title, or resetting it to an automatic label, removes that protection so the
+    normal auto-title path can run again.
+    """
+    title = str(raw_title or '').strip()[:80]
+    if not title:
+        title = 'Untitled'
+    manual_title = title.strip().casefold() not in AUTO_TITLE_LABELS
+    session.title = title
+    session.manual_title = manual_title
+    session.llm_title_generated = False
+    return title
+
+
+def mark_session_title_generated(session) -> None:
+    """Mark a session title as generated by the title model."""
+    session.llm_title_generated = True
+    session.manual_title = False
+
 
 def _truncate_at_last_user(messages):
     history = messages or []