Fix "Send All" folder action

[gschier]

Fixes a Send All regression where folder sends could appear stuck in "sending".

Root Cause

In plugin host handling for send_http_request_request, the initial response upsert used UpdateSource::Plugin, while later send updates used UpdateSource::Window. The older plugin-sourced model update could be replayed and overwrite the newer closed state.

Fix

Use UpdateSource::from_window_label(window.label()) for the initial upsert in crates-tauri/yaak-app/src/plugin_events.rs so all updates for that response are consistently window-scoped.

Validation

• Single-file change in crates-tauri/yaak-app/src/plugin_events.rs
• cargo check -p yaak-app could not fully complete in this environment due missing vendored resource (vendored/protoc/include).

Feedback reference: https://yaak.app/feedback/posts/send-all-isnt-working-anymore