permissions: Allow fullscreen video requests on macOS

On macOS, videos embedded in Zulip Desktop could not enter fullscreen
mode because the app's permission handler did not explicitly grant
fullscreen permissions.

This commit updates the `ipcRenderer.on("permission-request")` handler
to include fullscreen, in addition to existing permissions such as
notifications. With this change, video players (e.g., YouTube and
Zulip-embedded media) can properly request fullscreen.

Tested on macOS to confirm fullscreen now works, and on Windows/Linux
to ensure no regressions.

Fixes #1409.

Author: Ujjwal Sharma

app/renderer/js/main.ts

@@ -961,20 +961,22 @@ export class ServerManagerView {
         permissionCallbackId: number,
       ) => {
         const grant =
-          webContentsId === null
-            ? origin === "null" && permission === "notifications"
-            : (
-                await Promise.all(
-                  this.tabs.map(async (tab) => {
-                    if (!(tab instanceof ServerTab)) return false;
-                    const webview = await tab.webview;
-                    return (
-                      webview.webContentsId === webContentsId &&
-                      webview.properties.hasPermission?.(origin, permission)
-                    );
-                  }),
-                )
-              ).some(Boolean);
+          permission === "fullscreen"
+            ? true
+            : webContentsId === null
+              ? origin === "null" && permission === "notifications"
+              : (
+                  await Promise.all(
+                    this.tabs.map(async (tab) => {
+                      if (!(tab instanceof ServerTab)) return false;
+                      const webview = await tab.webview;
+                      return (
+                        webview.webContentsId === webContentsId &&
+                        webview.properties.hasPermission?.(origin, permission)
+                      );
+                    }),
+                  )
+                ).some(Boolean);
         console.log(
           grant ? "Granted" : "Denied",
           "permissions request for",