fix: exclude current session from session_search results

session_search was returning the current session if it matched the
query, which is redundant — the agent already has the current
conversation context. This wasted an LLM summarization call and a
result slot.

Added current_session_id parameter to session_search(). The agent
passes self.session_id and the search filters out any results where
either the raw or parent-resolved session ID matches. Both the raw
match and the parent-resolved match are checked to handle child
sessions from delegation.

Two tests added verifying the exclusion works and that other
sessions are still returned.

tests/tools/test_session_search.py

@@ -145,3 +145,62 @@ class TestSessionSearch:
         mock_db = object()
         result = json.loads(session_search(query="   ", db=mock_db))
         assert result["success"] is False
+
+    def test_current_session_excluded(self):
+        """session_search should never return the current session."""
+        from unittest.mock import MagicMock
+        from tools.session_search_tool import session_search
+
+        mock_db = MagicMock()
+        current_sid = "20260304_120000_abc123"
+
+        # Simulate FTS5 returning matches only from the current session
+        mock_db.search_messages.return_value = [
+            {"session_id": current_sid, "content": "test match", "source": "cli",
+             "session_started": 1709500000, "model": "test"},
+        ]
+        mock_db.get_session.return_value = {"parent_session_id": None}
+
+        result = json.loads(session_search(
+            query="test", db=mock_db, current_session_id=current_sid,
+        ))
+        assert result["success"] is True
+        assert result["count"] == 0
+        assert result["results"] == []
+
+    def test_current_session_excluded_keeps_others(self):
+        """Other sessions should still be returned when current is excluded."""
+        from unittest.mock import MagicMock
+        from tools.session_search_tool import session_search
+
+        mock_db = MagicMock()
+        current_sid = "20260304_120000_abc123"
+        other_sid = "20260303_100000_def456"
+
+        mock_db.search_messages.return_value = [
+            {"session_id": current_sid, "content": "match 1", "source": "cli",
+             "session_started": 1709500000, "model": "test"},
+            {"session_id": other_sid, "content": "match 2", "source": "telegram",
+             "session_started": 1709400000, "model": "test"},
+        ]
+        mock_db.get_session.return_value = {"parent_session_id": None}
+        mock_db.get_messages_as_conversation.return_value = [
+            {"role": "user", "content": "hello"},
+            {"role": "assistant", "content": "hi there"},
+        ]
+
+        # Mock the summarizer to return a simple summary
+        import tools.session_search_tool as sst
+        original_client = sst._async_aux_client
+        sst._async_aux_client = None  # Disable summarizer → returns None
+
+        result = json.loads(session_search(
+            query="test", db=mock_db, current_session_id=current_sid,
+        ))
+
+        sst._async_aux_client = original_client
+
+        assert result["success"] is True
+        # Current session should be skipped, only other_sid should appear
+        assert result["sessions_searched"] == 1
+        assert current_sid not in [r.get("session_id") for r in result.get("results", [])]