feat: Implement ticket commenting functionality

Adds the ability for users to comment on tickets, view comments, and distinguish between user and admin responses. Also introduces a new 'SUSPENDED' status for tickets and refactors database schema and API endpoints to support comments.

server/db.js

@@ -334,6 +334,19 @@ const initDb = async () => {
       )
     `);
 
+    // 10. Ticket Comments Table
+    await connection.query(`
+      CREATE TABLE IF NOT EXISTS ticket_comments (
+        id VARCHAR(36) PRIMARY KEY,
+        ticket_id VARCHAR(36) NOT NULL,
+        user_id VARCHAR(36) NOT NULL,
+        text TEXT NOT NULL,
+        created_at ${TIMESTAMP_TYPE} DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (ticket_id) REFERENCES tickets(id) ON DELETE CASCADE,
+        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+      )
+    `);
+
     // --- SEEDING ---
     const [rows] = await connection.query('SELECT * FROM settings WHERE id = 1');
     const defaultFeatures = {