feat: bot reset with hard confirm and event-driven purge

chat/state/entities.py

@@ -31,6 +31,46 @@ def _apply_you_authored(conn: Connection, e: Event) -> None:
     )
 
 
+@on("bot_reset")
+def _apply_bot_reset(conn: Connection, e: Event) -> None:
+    """Purge per-bot runtime state while preserving the bot's identity row.
+
+    Wipes chats hosted by this bot (with cascading chat-scoped tables),
+    memories owned by this bot, edges involving this bot, and the bot's own
+    activity row. The ``bots`` row itself is preserved so identity,
+    initial-relationship, and kickoff prose remain authored.
+    """
+    bot_id = e.payload["bot_id"]
+
+    chat_ids = [
+        row[0]
+        for row in conn.execute(
+            "SELECT id FROM chats WHERE host_bot_id = ?", (bot_id,)
+        ).fetchall()
+    ]
+    for chat_id in chat_ids:
+        conn.execute("DELETE FROM scenes WHERE chat_id = ?", (chat_id,))
+        conn.execute("DELETE FROM containers WHERE chat_id = ?", (chat_id,))
+        conn.execute("DELETE FROM chat_state WHERE chat_id = ?", (chat_id,))
+        conn.execute("DELETE FROM chats WHERE id = ?", (chat_id,))
+
+    # Activity for this bot's entity row (independent of chat_id since the
+    # ``activity`` table is keyed on entity_id).
+    conn.execute("DELETE FROM activity WHERE entity_id = ?", (bot_id,))
+
+    # Memories authored by this bot.
+    conn.execute("DELETE FROM memories WHERE owner_id = ?", (bot_id,))
+
+    # Edges in either direction involving this bot.
+    conn.execute(
+        "DELETE FROM edges WHERE source_id = ? OR target_id = ?",
+        (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.
+
+
 def get_bot(conn: Connection, bot_id: str) -> dict | None:
     row = conn.execute("SELECT * FROM bots WHERE id = ?", (bot_id,)).fetchone()
     if not row: