Function dispatch_to_renderers 

pub fn dispatch_to_renderers(state: &Arc<AppState>, event: &Event)

Forward a launcher event to every top-level renderer.

Excluded:

• Pool inventory labels (window-pool-* in pool.unpromoted OR pool.queue): no user UI yet. Two sub-states:
  • pool.unpromoted — spawning, renderer not ready.
  • pool.queue — renderer ready, waiting for promote. Both are hidden off-screen and would build stale InstancePanel state from launcher events the user never sees. The bridge uses state.user_visibility_snapshot() which atomically reads the pool inventory (unpromoted ∪ queue) and the browser registry under one host_state lock — a two-lock variant would race against promote_pool_window and let a just-promoted window slip through (or, worse, count a real user window in the close-cascade gate’s exclusion).
• Browser-pane labels (browser-pane-*): not top-level windows; have no InstancePanel.

Promoted pool windows (label still has the window-pool-* prefix but the entry is in NEITHER pool set) ARE included — they’re the user-visible torn-off windows. Pre-fix, a label-prefix-only check excluded them too, so torn-off windows stopped receiving launcher events post-promotion (InstancePanel drift, plus anything else listening to launcher events).

JSON payload uses serde_json::to_string, so any string content from the Event is escaped against quote / backtick injection at the JS-string boundary.