Complete private authentication, server integrations and activity reporting

Add Fabric/Forge version builds and Paper integration, preserve permanent player identities across renames, harden session authorization, and surface privacy-conscious launcher/server activity in the panel.

launcher/src-tauri/src/accounts.rs

@@ -134,6 +134,25 @@ fn save_panel_account(state: &AppState, panel: &str, auth: AuthResponse) -> Resu
     Ok(account)
 }
 
+pub async fn rename_panel(state: &AppState, username: &str, password: &str) -> Result<Account> {
+    if state.game.lock().unwrap().is_some() || state.task.lock().unwrap().as_ref().is_some_and(|t| !t.is_finished()) {
+        bail!("close Minecraft and wait for any installation to finish before changing your username");
+    }
+    let panel = state.panel_url().ok_or_else(|| anyhow!("no panel configured"))?;
+    let token = panel_token(state).ok_or_else(|| anyhow!("sign in to your server account first"))?;
+    let resp = state
+        .http
+        .put(format!("{panel}/api/v1/account/username"))
+        .bearer_auth(token)
+        .json(&json!({"username": username, "password": password}))
+        .send()
+        .await?;
+    if !resp.status().is_success() {
+        return Err(panel_error(resp).await);
+    }
+    save_panel_account(state, &panel, resp.json().await?)
+}
+
 pub fn add_offline(state: &AppState, username: &str) -> Result<Account> {
     let allowed = state.manifest.read().unwrap().as_ref().map(|m| m.auth.offline_local).unwrap_or(true);
     if !allowed {