fix: bot_reset cascades to guest references in other chats

chat/state/entities.py

@@ -66,6 +66,13 @@ def _apply_bot_reset(conn: Connection, e: Event) -> None:
         "DELETE FROM edges WHERE source_id = ? OR target_id = ?",
         (bot_id, bot_id),
     )
+
+    # Phase 2 cascade: clear guest references in other bots' chats so the host
+    # doesn't see a stale guest_bot_id pointing at this (now-purged) bot.
+    conn.execute(
+        "UPDATE chats SET guest_bot_id = NULL WHERE guest_bot_id = ?",
+        (bot_id,),
+    )
     # NOTE: bots row itself is preserved (identity, kickoff_prose intact).
     # NOTE: "you" activity (entity_id="you") may linger from a deleted chat;
     # acceptable for v1 — Phase 1.5 cleanup if needed.

tests/test_reset.py

@@ -183,3 +183,167 @@ def test_bot_list_renders_reset_form(client, tmp_path):
     assert response.status_code == 200
     assert "Reset" in response.text
     assert "confirm_name" in response.text
+
+
+def _seed_two_bots_with_guest_link(
+    db: Path, *, extra_events: list[dict] | None = None
+) -> None:
+    """Seed bot_a + bot_b, each hosting their own chat, with bot_b a guest in chat_bot_a.
+
+    ``extra_events`` is appended after the guest_added event and projected
+    together with the rest of the seed (so handlers run only once per event).
+    """
+    with open_db(db) as conn:
+        # bot_a + its chat
+        append_event(
+            conn,
+            kind="bot_authored",
+            payload={
+                "id": "bot_a",
+                "name": "BotA",
+                "persona": "thoughtful",
+                "voice_samples": [],
+                "traits": [],
+                "backstory": "",
+                "initial_relationship_to_you": "coworker",
+                "kickoff_prose": "",
+            },
+        )
+        append_event(
+            conn,
+            kind="chat_created",
+            payload={
+                "id": "chat_bot_a",
+                "host_bot_id": "bot_a",
+                "initial_time": "2026-04-26T20:00:00+00:00",
+                "narrative_anchor": "Day 1",
+                "weather": "",
+            },
+        )
+        # bot_b + its own chat
+        append_event(
+            conn,
+            kind="bot_authored",
+            payload={
+                "id": "bot_b",
+                "name": "BotB",
+                "persona": "curious",
+                "voice_samples": [],
+                "traits": [],
+                "backstory": "",
+                "initial_relationship_to_you": "friend",
+                "kickoff_prose": "",
+            },
+        )
+        append_event(
+            conn,
+            kind="chat_created",
+            payload={
+                "id": "chat_bot_b",
+                "host_bot_id": "bot_b",
+                "initial_time": "2026-04-26T20:00:00+00:00",
+                "narrative_anchor": "Day 1",
+                "weather": "",
+            },
+        )
+        # bot_b joins chat_bot_a as a guest.
+        append_event(
+            conn,
+            kind="guest_added",
+            payload={
+                "chat_id": "chat_bot_a",
+                "guest_bot_id": "bot_b",
+            },
+        )
+        for ev in extra_events or []:
+            append_event(conn, kind=ev["kind"], payload=ev["payload"])
+        project(conn)
+
+
+def test_reset_clears_guest_reference_in_other_chats(client, tmp_path):
+    db = tmp_path / "test.db"
+    _seed_two_bots_with_guest_link(db)
+
+    # Sanity-check the seed: bot_b is the guest in bot_a's chat.
+    from chat.state.world import get_chat
+    with open_db(db) as conn:
+        assert get_chat(conn, "chat_bot_a")["guest_bot_id"] == "bot_b"
+        assert get_chat(conn, "chat_bot_b") is not None
+
+    response = client.post(
+        "/bots/bot_b/reset",
+        data={"confirm_name": "BotB"},
+        follow_redirects=False,
+    )
+    assert response.status_code == 303
+
+    with open_db(db) as conn:
+        # The guest reference in bot_a's chat is cleared.
+        chat_a = get_chat(conn, "chat_bot_a")
+        assert chat_a is not None
+        assert chat_a["guest_bot_id"] is None
+
+        # bot_b's own chat is gone (Phase 1 host purge behavior).
+        assert get_chat(conn, "chat_bot_b") is None
+
+        # bot_a is untouched.
+        assert conn.execute(
+            "SELECT COUNT(*) FROM bots WHERE id = 'bot_a'"
+        ).fetchone()[0] == 1
+
+
+def test_reset_purges_guest_memories_from_other_chats(client, tmp_path):
+    db = tmp_path / "test.db"
+    _seed_two_bots_with_guest_link(
+        db,
+        extra_events=[
+            # bot_b is a guest in chat_bot_a and remembers things from there.
+            {
+                "kind": "memory_written",
+                "payload": {
+                    "owner_id": "bot_b",
+                    "chat_id": "chat_bot_a",
+                    "pov_summary": "Met BotA; she was tense.",
+                    "witness_you": 1,
+                    "witness_host": 1,
+                    "witness_guest": 1,
+                    "significance": 3,
+                },
+            },
+            # And a memory from bot_b's own chat for good measure.
+            {
+                "kind": "memory_written",
+                "payload": {
+                    "owner_id": "bot_b",
+                    "chat_id": "chat_bot_b",
+                    "pov_summary": "A quiet evening at home.",
+                    "witness_you": 1,
+                    "witness_host": 1,
+                    "witness_guest": 0,
+                    "significance": 1,
+                },
+            },
+        ],
+    )
+
+    with open_db(db) as conn:
+        # Sanity: bot_b owns 2 memories pre-reset, one in each chat.
+        assert conn.execute(
+            "SELECT COUNT(*) FROM memories WHERE owner_id = 'bot_b'"
+        ).fetchone()[0] == 2
+
+    response = client.post(
+        "/bots/bot_b/reset",
+        data={"confirm_name": "BotB"},
+        follow_redirects=False,
+    )
+    assert response.status_code == 303
+
+    with open_db(db) as conn:
+        # ALL of bot_b's memories are gone, including the cross-chat one in chat_bot_a.
+        assert conn.execute(
+            "SELECT COUNT(*) FROM memories WHERE owner_id = 'bot_b'"
+        ).fetchone()[0] == 0
+        assert conn.execute(
+            "SELECT COUNT(*) FROM memories WHERE owner_id = 'bot_b' AND chat_id = 'chat_bot_a'"
+        ).fetchone()[0] == 0