fix(session_search): cap title-match discovery entries like FTS hits

_title_match_result shaped its bookends and window with no max_content_len while
_bookend/_hydrate_hit cap FTS hits at 1200/4000, so a session found by title
could still return one 74K tool result verbatim. Same caps, same metadata.

tests/tools/test_session_search.py

@@ -508,6 +508,19 @@ class TestReadShape:
         assert big["original_content_chars"] == 80_000
         assert sum(len(m.get("content") or "") for m in result["messages"]) < 5_000
 
+    def test_title_match_entry_caps_content_like_fts_hits(self, db):
+        """A session-title match is a discovery entry: bookends 1200, window 4000, same as FTS hits."""
+        db.create_session("s_titled", source="cli")
+        db.set_session_title("s_titled", "quasar ledger reconciliation")
+        db.append_message("s_titled", role="user", content="reconcile the quasar ledger")
+        db.append_message("s_titled", role="tool", content="y" * 80_000)
+        db.end_session("s_titled", "cli_exit")
+        result = json.loads(session_search(query="quasar ledger reconciliation", db=db, detail="full"))
+        entry = next(r for r in result["results"] if r["matched_role"] == "session_title")
+        shaped = entry["bookend_start"] + entry["messages"] + entry["bookend_end"]
+        big = [m for m in shaped if m.get("original_content_chars") == 80_000]
+        assert big and all(m["content_truncated"] and len(m["content"]) <= 4001 for m in big)
+
 
 # =========================================================================
 # Session links — the value the agent writes to point the user at a session

tools/session_search_tool.py

@@ -294,14 +294,17 @@ def _title_match_result(db, query: str, current_lineage_root: Optional[str]) ->
         lambda: db.get_anchored_view(session_id, anchor_id, window=5, bookend=3), {},
         "get_anchored_view failed for title match %s/%s", session_id, anchor_id)
     title = session_meta.get("title") or title_query
-    def shape(key, fallback, anchor=None):
-        return [_shape_message(m, anchor_id=anchor) for m in (view.get(key) or fallback)]
+    # Same caps as FTS hits (_bookend / _hydrate_hit): a title match is a discovery entry too.
+    def shape(key, fallback, anchor=None, max_content_len=1200):
+        return [_shape_message(m, anchor_id=anchor, max_content_len=max_content_len)
+                for m in (view.get(key) or fallback)]
     return {**_discovery_entry(
         lineage_root, session_id=session_id, when=_format_timestamp(session_meta.get("started_at")),
         source=session_meta.get("source", "unknown"), model=session_meta.get("model") or "unknown",
         title=title, matched_role="session_title", match_message_id=anchor_id,
         snippet=f"Session title matched: {title}",
-        bookend_start=shape("bookend_start", messages[:3]), messages=shape("window", messages[:5], anchor_id),
+        bookend_start=shape("bookend_start", messages[:3]),
+        messages=shape("window", messages[:5], anchor_id, max_content_len=4000),
         bookend_end=shape("bookend_end", messages[-3:]), messages_before=view.get("messages_before", 0),
         messages_after=view.get("messages_after", max(len(messages) - 5, 0)), detail="full"),
         "_lineage_root": lineage_root}