fix: Save As with Live in the background - #188

What changed

• Save As opens and binds the Live Set Save panel while Live is behind other apps or on another desktop, reading the panel through Live's focused accessibility window.
• Live is brought to the visible desktop only before the folder, filename and Save steps; the commit waits up to 2 s for Save to enable.
• A filename edit that does not read back now cancels the panel the tool opened instead of leaving it open.
• A panel that is opened but cannot be bound, or a failed show of Live, closes that panel and reports saveAsRecovery.status: "cancelled".

Why

• The Save panel disables Save and New Folder while it is not on the visible desktop, and its windows are not listed off the visible Space, so Save As failed when Live was not frontmost.

Verification

• node --test test/live-set-save-dialog.test.mjs test/live-set-host.test.mjs test/live-set-tools.test.mjs: 49 pass, 0 fail
• npm run verify:package, if packaging, the CLI, or the bridge install changed
• npm run docs:tools, if a tool contract changed
• Checked against a running Live, if Live-side behavior changed (Live version: 12.4.16): Save As of an untitled Set returned saved: true and wrote score Project/score.als

Contract impact

• No tool, resource, or prompt contract change
• Tool contract changed and reference/tools.md regenerated