fix(sessions): pinned-skip note counts pinned rows, not spared ancestors

_note_pinned_skipped diffed count_prune_matches(include_pinned=True/False)
with whole_lineages on for prune. Excluding a pinned tip turns it into an
unmatched continuation, so its unpinned compression ancestors drop out of
the "without" count too and the note reported them as pinned (chain
a -> a-2 -> a-3 with only a-3 pinned said "3 pinned sessions").

Count plain filter matches for the note; the delete itself is unchanged.
count_prune_matches has no other caller that needs whole_lineages, so the
keyword goes back to base's signature.

hermes_cli/sessions_cmd.py

@@ -639,8 +639,9 @@ def _note_pinned_skipped(db, filters, action):
     """Tell the user how many pinned rows bulk prune/archive spared (pin = durable keep; only
     `prune --include-pinned` opts in, archive always spares them)."""
     _base = {k: v for k, v in filters.items() if k != "include_pinned"}
-    with_pinned, without = (int(db.count_prune_matches(**_base, include_pinned=flag, whole_lineages=action == "prune"))
-                            for flag in (True, False))
+    # Count matching pinned rows only: whole-lineage selection would also drop the unpinned
+    # ancestors a pinned tip spares, and report them as pinned.
+    with_pinned, without = (int(db.count_prune_matches(**_base, include_pinned=flag)) for flag in (True, False))
     skipped = max(with_pinned - without, 0)
     if not skipped:
         return

hermes_state_maintenance.py

@@ -250,10 +250,10 @@ class SessionMaintenanceMixin:
                     FROM sessions s WHERE {where}
                     ORDER BY last_active ASC, s.started_at ASC""", params)]
 
-    def count_prune_matches(self, older_than_days: Optional[float] = None, source: str = None, *,
-                            whole_lineages: bool = False, **filters) -> int:
+    def count_prune_matches(self, older_than_days: Optional[float] = None, source: str = None,
+                            **filters) -> int:
         """Count-only :meth:`list_prune_candidates` (CLI reports spared pinned sessions)."""
-        where, params = self._prune_where(older_than_days, source, filters, whole_lineages=whole_lineages)
+        where, params = self._prune_where(older_than_days, source, filters)
         return int(self._read_one(f"SELECT COUNT(*) FROM sessions s WHERE {where}", params)[0])
 
     def count_open_prune_matches(self, older_than_days: Optional[float] = None, source: str = None, *,

tests/hermes_state/test_prune_activity_recency.py

@@ -1,6 +1,7 @@
 import time
 from contextlib import closing
 import pytest
+from hermes_cli.sessions_cmd import _note_pinned_skipped
 from hermes_state import SessionDB
 
 
@@ -47,7 +48,7 @@ def test_prune_sessions_respects_touch_session_activity(tmp_path):
         assert db.get_session("active_by_heartbeat") is not None
 
 
-def test_prune_keeps_the_compressed_segments_of_a_chat_still_in_use(tmp_path):
+def test_prune_keeps_the_compressed_segments_of_a_chat_still_in_use(tmp_path, capsys):
     """A rotated conversation ages as one: its old compressed-away segments stay while a later segment
     is still in use, and go together once the whole chat is idle. The CLI/dashboard preview lists what prune deletes."""
     with closing(SessionDB(tmp_path / "state.db")) as db:
@@ -74,6 +75,13 @@ def test_prune_keeps_the_compressed_segments_of_a_chat_still_in_use(tmp_path):
         db._conn.commit()
 
         idle = {"idle", "idle-2", "idle-3"}
+        # The CLI pinned-skip note counts pinned rows, not the unpinned ancestors a pinned tip spares.
+        db._conn.execute("UPDATE sessions SET pinned = 1 WHERE id = 'idle-3'")
+        db._conn.commit()
+        _note_pinned_skipped(db, {"older_than_days": 90, "lineage_tips_only": False}, "prune")
+        assert "Note: 1 pinned session also match" in capsys.readouterr().out
+        db._conn.execute("UPDATE sessions SET pinned = 0 WHERE id = 'idle-3'")
+        db._conn.commit()
         assert {c["id"] for c in db.list_prune_candidates(older_than_days=90, whole_lineages=True)} == idle
         assert db.prune_sessions(older_than_days=90) == len(idle)
         assert db.get_compression_lineage("live-3") == ["live", "live-2", "live-3"]