Slate v2 slate-browser Ready Cut

Supporting plan. For current queue and roadmap truth, see master-roadmap.md.

Goal

Continue Phase 8 by tightening slate-browser around the real ready contract.

Scope

• remove the legacy waitFor* option aliases from the Playwright surface
• keep ready as the maintained setup contract
• sync package/docs and roadmap language accordingly

Evidence

• maintained browser tests already use ready
• the only remaining waitFor* option references are inside packages/slate-browser/src/playwright/index.ts
• the roadmap explicitly says not to preserve awkward slate-browser APIs just for inertia

Progress

• removed waitForEditable, waitForPlaceholderVisible, waitForSelector, and waitForText from the Playwright options surface
• kept default openExample(...) behavior honest by defaulting to ready: { editor: 'visible' }
• updated packages/slate-browser/README.md to present ready as the only maintained setup contract
• synced the Phase 8 roadmap/docs stack in plate-2
• verification:
  • no remaining waitFor* option references in /Users/zbeyens/git/slate-v2
  • yarn workspace slate-browser test
  • browser proof on port 3010: bash ./scripts/run-slate-browser-local.sh 3010 /examples/paste-html "yarn build:slate-browser:playwright && yarn exec playwright test playwright/integration/examples/paste-html.test.ts playwright/integration/examples/links.test.ts --project=chromium --workers=1"
  • yarn prettier --check packages/slate-browser/src/playwright/index.ts packages/slate-browser/README.md