playhtml: reevaluate cursor render predicates

[spencerc99]

Summary

• Reevaluate every current remote cursor when shouldRenderCursor changes.
• Reuse the existing cursor update path so filtered cursors are removed and newly allowed cursors are recreated without waiting for another peer event.
• Add focused regression coverage for both visibility directions and a playhtml patch changeset.

Root cause

CursorClientAwareness.configure() updated the stored cursor options, but shouldRenderCursor was only read by updateCursor(). Existing remote cursor DOM was therefore left in its prior state until that peer published another cursor update.

Validation

• bun run test -- src/cursors/__tests__/configure-render-filter.test.ts (2 tests)
• bun run test in packages/playhtml (51 files, 501 tests)
• bun run build in packages/common
• bun run build in packages/playhtml
• bunx tsc --noEmit in packages/playhtml
• Real-browser validation with two independent clients: a current remote cursor disappears when the predicate filters it and reappears when the predicate allows it, with no new peer movement.

Docs and starters

No docs change is needed because the documented shouldRenderCursor signature and usage are unchanged. The fix makes configure() honor the existing contract immediately. No starter update is needed because imports, options, markup, and CSS are unchanged.

[spencerc99]

Preview evidence

Changing shouldRenderCursor immediately hides and restores current remote cursor DOM without another peer update.

Open preview · Review all evidence · Commit fb87f5a

Current remote cursor filtered

Two clients remain online while the current remote cursor DOM is removed immediately after the predicate changes to false.

Open captured page · 1280×720

Current remote cursor restored

The same current remote cursor reappears immediately after the predicate changes to true, without another peer movement.

Open captured page · 1280×720

_{Published by PR Evidence. Media is temporary and is removed after retention expires.}

[pkg-pr-new]

Open in StackBlitz

bun add https://pkg.pr.new/@playhtml/common@345

bun add https://pkg.pr.new/playhtml@345

bun add https://pkg.pr.new/@playhtml/react@345

commit: fb87f5a