Add guild_member_stats table and update permissions for Discord members

- Created a new table `guild_member_stats` to track message counts and voice activity for users in each guild.
- Updated the database schema and models to include the new table.
- Added a new permission entry for `discord_members` in the `webapp_page_permission` table.
- Enhanced the webapp to include links and settings for managing Discord member statistics.

database/schema.sql

@@ -99,6 +99,15 @@ CREATE TABLE IF NOT EXISTS `member_invites` (
 	`join_date` DATETIME NOT NULL
 );
 
+CREATE TABLE IF NOT EXISTS `guild_member_stats` (
+	`guild_id` VARCHAR(64) NOT NULL,
+	`user_id` VARCHAR(64) NOT NULL,
+	`message_count` INTEGER NOT NULL DEFAULT 0,
+	`voice_seconds` INTEGER NOT NULL DEFAULT 0,
+	`updated_at` DATETIME,
+	PRIMARY KEY (`guild_id`, `user_id`)
+);
+
 CREATE TABLE IF NOT EXISTS `twitch_link_filter` (
 	id INTEGER PRIMARY KEY AUTOINCREMENT,
 	`enabled` BOOLEAN NOT NULL DEFAULT FALSE,