fix(session-search): strip ANSI from recalled messages

Recalled session messages can carry raw ANSI escape sequences (e.g.
archived terminal output), which then re-enter the model's context.
Strip them in _shape_message before content is truncated/returned,
reusing tools.ansi_strip.strip_ansi.

Re-applied onto current main (the original hunk predates the
max_content_len truncation in _shape_message; stripping happens on the
raw content before truncation so escape bytes never count against the
budget). Extracted from #40276.

tests/tools/test_session_search.py

@@ -272,6 +272,19 @@ class TestReadShape:
         assert len(result["messages"]) == 5
         assert result["session_meta"]["title"] == "Building the Modpack"
 
+    def test_read_strips_ansi_sequences_from_messages(self, db):
+        db.create_session("s_ansi", source="cli")
+        db.append_message("s_ansi", role="user", content="plain")
+        db.append_message(
+            "s_ansi", role="assistant", content="\u001b[31mred text\u001b[0m and more"
+        )
+        db._conn.commit()
+        result = json.loads(session_search(session_id="s_ansi", db=db))
+        assert result["success"] is True
+        rendered = [m["content"] for m in result["messages"] if m.get("content")]
+        assert any(text == "red text and more" for text in rendered)
+        assert all("\u001b" not in text for text in rendered)
+
     def test_read_truncates_large_session(self, db):
         db.create_session("s_big", source="cli")
         for i in range(50):

tools/session_search_tool.py

@@ -247,6 +247,12 @@ def _shape_message(
     is added so callers know the payload was bounded.
     """
     raw_content = m.get("content")
+    if isinstance(raw_content, str) and "\x1b" in raw_content:
+        # Recalled messages can carry ANSI escape sequences (e.g. archived
+        # terminal output). Strip them before returning content to the model.
+        from tools.ansi_strip import strip_ansi
+
+        raw_content = strip_ansi(raw_content)
     if max_content_len and raw_content and len(raw_content) > max_content_len:
         content = raw_content[:max_content_len] + "…"
         truncated = True