Add workspace screen sharing (#64)

Add workspace selection to the screen-sharing picker with pinned capture, privacy filtering and bounded capture resources. Refresh captured tab labels when title or app-ID metadata changes.

portal/src/restore.rs

@@ -148,6 +148,7 @@ impl Restore {
             || app.len() > 512
             || sources.is_empty()
             || sources.len() > 16
+            || sources.iter().any(|source| !source.is_monitor())
             || !(1..=2).contains(&mode)
         {
             return None;