Added full message handling system with archive view, pagination, and send support

- Implemented message inbox and archived messages view
- Added pagination logic to both inbox and archive handlers
- Integrated message sending functionality with CSRF protection
- Updated schema to include `archived_at` timestamp
- Included archive button and logic with feedback flash messaging
- Fixed message dropdown routing and rendering in topbar
- Cleaned up template load paths and error handling

storage/schema.go

@@ -115,12 +115,13 @@ const SchemaUsersMessages = `
 CREATE TABLE IF NOT EXISTS users_messages (
 	id INTEGER PRIMARY KEY AUTOINCREMENT,
 	senderId INTEGER NOT NULL REFERENCES users(id),
-	recipientId int,
+	recipientId INTEGER NOT NULL REFERENCES users(id),
 	subject TEXT NOT NULL,
 	message TEXT,
 	is_read BOOLEAN DEFAULT FALSE,
 	is_archived BOOLEAN DEFAULT FALSE,
-	created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+	created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+	archived_at TIMESTAMP
 );`
 
 const SchemaUsersNotifications = `