fix(claude-code): retain on SessionEnd even when retainEveryNTurns > 1 (#1152)

With retainEveryNTurns > 1, short Claude Code sessions (fewer turns
than the interval) never hit a retain boundary and their transcript is
silently dropped on session close. SessionEnd previously only stopped
the daemon and did not flush.

Refactor retain.py by splitting main() into:
  - main(): reads stdin, delegates to run_retain(hook_input, force=False)
  - run_retain(hook_input, force=False): the retain body; force=True
    bypasses the retainEveryNTurns turn-counter skip so a caller can
    request a final flush.

session_end.py now imports run_retain and calls it with force=True
before stopping the daemon, guaranteeing that every session lands on
disk regardless of length or retain cadence.

Net effect: `retainEveryNTurns: 10` (the default) stops silently losing
sessions under 10 turns.

Co-authored-by: biostartechnology <info@biostartechnology.com>

Author: starbit-biostar

hindsight-integrations/claude-code/scripts/retain.py

@@ -69,21 +69,14 @@ def read_transcript(transcript_path: str) -> list:
     return messages
 
 
-def main():
+def run_retain(hook_input: dict, force: bool = False) -> None:
     config = load_config()
 
     if not config.get("autoRetain"):
         debug_log(config, "Auto-retain disabled, exiting")
         return
 
-    # Read hook input from stdin
-    try:
-        hook_input = json.load(sys.stdin)
-    except (json.JSONDecodeError, EOFError):
-        print("[Hindsight] Failed to read hook input", file=sys.stderr)
-        return
-
-    debug_log(config, f"Stop hook input keys: {list(hook_input.keys())}")
+    debug_log(config, f"Retain hook_input keys: {list(hook_input.keys())} force={force}")
 
     session_id = hook_input.get("session_id", "unknown")
     transcript_path = hook_input.get("transcript_path", "")
@@ -102,8 +95,8 @@ def main():
     retain_full_window = False
     messages_to_retain = all_messages
 
-    # Respect retainEveryNTurns in both modes
-    if retain_every_n > 1:
+    # Respect retainEveryNTurns in both modes, unless force=True (SessionEnd final retain)
+    if retain_every_n > 1 and not force:
         turn_count = increment_turn_count(session_id)
         if turn_count % retain_every_n != 0:
             next_at = ((turn_count // retain_every_n) + 1) * retain_every_n
@@ -226,6 +219,15 @@ def _resolve_template(value: str) -> str:
         print(f"[Hindsight] Retain failed: {e}", file=sys.stderr)
 
 
+def main():
+    try:
+        hook_input = json.load(sys.stdin)
+    except (json.JSONDecodeError, EOFError):
+        print("[Hindsight] Failed to read hook input", file=sys.stderr)
+        return
+    run_retain(hook_input, force=False)
+
+
 if __name__ == "__main__":
     try:
         main()

hindsight-integrations/claude-code/scripts/session_end.py

@@ -28,6 +28,15 @@ def main():
 
     debug_log(config, f"SessionEnd hook, reason: {hook_input.get('reason', 'unknown')}")
 
+    # Force a final retain before stopping the daemon — guarantees short sessions
+    # (fewer turns than retainEveryNTurns) still land on disk.
+    if config.get("autoRetain") and hook_input.get("transcript_path"):
+        try:
+            from retain import run_retain
+            run_retain(hook_input, force=True)
+        except Exception as e:
+            print(f"[Hindsight] SessionEnd final retain error: {e}", file=sys.stderr)
+
     # Stop daemon if we started it
     def _dbg(*a):
         debug_log(config, *a)