Add Discord OAuth2 login and refactor authentication

Implemented Discord OAuth2 authentication flow with a new Discord.cs handler and integrated it into Program.cs. Refactored authentication logic to use shared JsonSerializerOptions from LauncherConstants. Updated BashUtils with cross-platform URL opening, improved MojangAPI to use shared HttpClient, and enhanced frontend login and log handling in logged.js and login.js.

wwwroot/assets/js/logged.js

@@ -1,6 +1,7 @@
 const buttons = document.querySelectorAll("button[frame]")
 const dynmapFrame = document.querySelector("article.frame.dynmap > iframe") 
 const capesSelector = document.querySelector("article.capes > div.capes")
+const logsContainer = document.querySelector("div.container.logs")
 
 let viewerInstance = new skinview3d.SkinViewer({
     canvas: document.getElementById("skin"),
@@ -99,7 +100,7 @@ window.initSkin = async function initSkin() {
         canvas: document.getElementById("skin"),
         width: container.clientWidth,
         height: container.clientHeight,
-        skin: `https://yggdrasil.azures.fr/textures/${profile.skins.find(skin => skin.state == "ACTIVE").url}`.replace(/\/+$/, "")
+        skin: `https://yggdrasil.azures.fr/textures/${profile.skins.find(skin => skin.state == "ACTIVE").url.replace(/^\//, "")}`
     })
 
     const activeCape = window.profile.capes.find(s => s.state === "ACTIVE") || null
@@ -228,6 +229,18 @@ window.changeUsername = async function changeUsername(newName) {
     }
 }
 
+window.gamelog = {}
+
+window.gamelog.put = async function put(log) {
+    const logElement = document.createElement("p")
+    logElement.innerText = log
+    logsContainer.appendChild(log)
+}
+
+window.gamelog.clear = async function clear() {
+    logsContainer.innerHTML = ""
+}
+
 await initSkin()
 await initSettings()
 await initCapesSelector()

wwwroot/assets/js/login.js

@@ -17,22 +17,32 @@ async function login() {
     const username = document.querySelector("#username").value
     const password = document.querySelector("#password").value
     const result = await system.call("auth::lentia", { username, password })
-    if (result.success == false) {
-        await system.call("dialog::error", { 
-            title: result.error.error,
-            message: result.error.errorMessage 
-        })
-    }
+    await processLoginResult(result)
 }
 
 function clearPassword() {
     password.value = ""
 }
 
-function requestLoginWithOAuth2() {
+async function requestLoginWithOAuth2() {
     showFrame("oauth2")
     hideInformation()
     showLoadingBar()
+    const result = await system.call("oauth2::discord")
+    await processLoginResult(result, true)
+}
+
+async function processLoginResult(payload, showDefaultPage = false) {
+    if (payload.success == false) {
+        await system.call("dialog::error", { 
+            title: payload.error.error,
+            message: payload.error.errorMessage 
+        })
+        if (showDefaultPage) {
+            hideLoadingBar()
+            showFrame("provider")
+        }
+    }
 }
 
 hideLoadingBar()