fix(portal): reject frames before format negotiation to prevent zero-dimension encoder init

src/cap_portal.rs

@@ -326,15 +326,21 @@ fn pipewire_thread(ctx: PwThreadCtx) {
                     pts_val
                 };
 
+                let Some((width, height, format, modifier)) = format_info.get() else {
+                    unsafe { stream.queue_raw_buffer(raw_buf) };
+                    return;
+                };
+                if width == 0 || height == 0 || format == 0 {
+                    unsafe { stream.queue_raw_buffer(raw_buf) };
+                    return;
+                }
+
                 let dup_fd = unsafe { libc::dup(fd) };
                 if dup_fd < 0 {
                     unsafe { stream.queue_raw_buffer(raw_buf) };
                     return;
                 }
 
-                let (width, height, format, modifier) =
-                    format_info.get().unwrap_or((0, 0, 0, 0));
-
                 let frame = PwDmaBufFrame {
                     fd: unsafe { OwnedFd::from_raw_fd(dup_fd) },
                     offset,