feat: implement dynamic server list loading from API

Add internal/api package to fetch server list from /api/servers.json endpoint

Replace hardcoded server list with dynamic API call

Implement loading states, error handling, and refresh capability

internal/ui/ui.go

@@ -5,6 +5,7 @@ import (
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/app"
 
+	"gitea.mrixs.me/Mrixs/MrixsCraft-launcher/internal/api"
 	"gitea.mrixs.me/Mrixs/MrixsCraft-launcher/internal/auth"
 	"gitea.mrixs.me/Mrixs/MrixsCraft-launcher/internal/config"
 	"gitea.mrixs.me/Mrixs/MrixsCraft-launcher/internal/ui/screens"
@@ -20,12 +21,13 @@ func Launch(client *auth.Client, session *auth.Session, settings config.Settings
 	w.Resize(fyne.NewSize(float32(settings.Width), float32(settings.Height)))
 	w.CenterOnScreen()
 
-	// TODO: fetch from /api/servers.json
-	serverList := []screens.Modpack{
-		{Slug: "hitech", Name: "HiTech 1.21"},
-		{Slug: "vanilla", Name: "Vanilla 1.20"},
-	}
+					// State for server list loading
+	var serverList []screens.Modpack
+	var isServerListLoading bool
+	var serverListError error
+	_ = serverListError // Use variable to prevent "declared and not used" error
 
+	// Callback functions
 	onPlay := func() {
 		// TODO: launch selected modpack
 	}
@@ -38,15 +40,38 @@ func Launch(client *auth.Client, session *auth.Session, settings config.Settings
 		})
 	}
 
-	content := screens.MainScreen(w, client, session, serverList, onPlay, onSettings)
+	// Function to refresh server list
+	var refreshServerList func()
+	refreshServerList = func() {
+		isServerListLoading = true
+		serverListError = nil
+		// Update UI to show loading state
+		content := screens.MainScreen(w, client, session, serverList, onPlay, onSettings, refreshServerList, isServerListLoading, serverListError)
+		w.SetContent(content)
+
+		// Fetch server list in goroutine to avoid blocking UI
+		go func() {
+			serverList, serverListError = api.FetchServerList(settings.ServerURL)
+			isServerListLoading = false
+			// Update UI with result
+			content := screens.MainScreen(w, client, session, serverList, onPlay, onSettings, refreshServerList, isServerListLoading, serverListError)
+			w.SetContent(content)
+		}()
+	}
+
+	// Initial load of server list
+	content := screens.MainScreen(w, client, session, serverList, onPlay, onSettings, refreshServerList, isServerListLoading, serverListError)
 	w.SetContent(content)
 
+	// Start fetching server list in background
+	go refreshServerList()
+
 	// If no session, show login modal after the window is rendered.
 	if session == nil {
 		w.Show()
 		screens.LoginScreen(w, client, func(sess *auth.Session) {
 			// Refresh UI with logged-in state.
-			content := screens.MainScreen(w, client, sess, serverList, onPlay, onSettings)
+			content := screens.MainScreen(w, client, sess, serverList, onPlay, onSettings, refreshServerList, isServerListLoading, serverListError)
 			w.SetContent(content)
 		})
 	}