Add missing database indexes to improve performance

Author: claude

model/sql/migrations/0016-add-missing-indexes.sql

@@ -0,0 +1,13 @@
+-- +migrate Up
+
+ALTER TABLE `quotes`
+    ADD INDEX `chat_id` (`chat_id`);
+
+ALTER TABLE `reminders`
+    ADD INDEX `time` (`time`);
+
+ALTER TABLE `reminders`
+    ADD INDEX `chat_id_time` (`chat_id`, `time`);
+
+ALTER TABLE `reminders`
+    ADD INDEX `user_id_time` (`user_id`, `time`);