Add core models, DTOs, and services for EchoHub chat application

- Created User, Channel, Message, and ServerInfo models with necessary properties.
- Added DTOs for user profiles, server information, and message handling.
- Implemented JWT authentication service for user login and token generation.
- Developed Entity Framework Core DbContext for database interactions.
- Introduced SignalR ChatHub for real-time messaging and presence tracking.
- Implemented file storage and image to ASCII conversion services.
- Set up CORS and middleware for API endpoints.
- Created launch settings and development configuration for server and web projects.

src/EchoHub.Server/Properties/launchSettings.json

@@ -0,0 +1,23 @@
+{
+	"$schema": "https://json.schemastore.org/launchsettings.json",
+	"profiles": {
+		"http": {
+			"commandName": "Project",
+			"dotnetRunMessages": true,
+			"launchBrowser": true,
+			"applicationUrl": "http://localhost:5000",
+			"environmentVariables": {
+				"ASPNETCORE_ENVIRONMENT": "Development"
+			}
+		},
+		"https": {
+			"commandName": "Project",
+			"dotnetRunMessages": true,
+			"launchBrowser": true,
+			"applicationUrl": "https://localhost:7171;http://localhost:5189",
+			"environmentVariables": {
+				"ASPNETCORE_ENVIRONMENT": "Development"
+			}
+		}
+	}
+}