Keep the comment composer clear of selected text

[minwookshin]

🐛 Fixes the draft comment composer covering or detaching from selected text; related to #5127.
🧭 Task plan: docs/plans/2026-09-28-plate-5134-main-comment-selection.md
🟢 High confidence in the scoped placement fix.

Phase	🧪 Tests	🌐 Browser
Reproduced	➖ N/A — browser geometry failure	🔴 On original main, the composer covered the first selected line near the top of a 900×330 viewport and detached from the selection near the bottom.
Verified	🟢 pnpm check, website typecheck, registry source/changelog checks, clean structured review	🟢 Real /blocks/editor-ai proof: top/bottom placement, backward multi-block selection, and scroll-driven flip kept the marked range clear with no console/request/page errors.

✅ Outcome Draft comments stay next to the full selected range and keep it clear whenever the composer fits on either side. This targets main as requested.

⚠️ Caveat When neither side fits the full selection, standard Radix shift and available-height behavior applies. Browser proof covers Chrome with the real registry components; other engines and physical devices were not tested. CI owns generated registry payloads.

🏗️ Design Preserve the focus block before collapsing the selection. Merge the live rectangles of every draft-marked leaf through @platejs/floating; let Radix own flip, shift, offset, and collision policy; use Radix's always update strategy only while drafting so the virtual range follows editor scrolling. Existing discussion and suggestion anchoring is unchanged.

🧪 Verified pnpm check, pnpm g:build, pnpm --filter www typecheck, pnpm lint:fix, registry source/changelog validation, focused browser geometry, and structured local review passed. The copied registry item declares @platejs/floating; no published package API changed.

[codesandbox]

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[changeset-bot]

⚠️ No Changeset found

Latest commit: c4516b9

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[minwookshin]

Synced with current next; Base UI and Radix placement checks pass on the pushed commit (6/6 in Chrome).
Broader check blockers are documented in the PR description.

[zbeyens]

next has no release lane yet. Feel free to PR against main instead.

[minwookshin]

Updated this against main and verified short, wrapped, and multi-block selections. Local pnpm check and the website typecheck pass; the fork workflows are waiting for maintainer approval.

[zbeyens]

next has no release lane yet. Feel free to PR against main instead.

Resolved and replayed on be74f847d26d074c081e63fb1ce1be68aa4ac686: PR #5134 targets main; its dedicated task plan exists at this exact head and names only PR #5134. Full local checks and focused browser proof pass.

[zbeyens]

Autoclosure receipt

Exact head: c4516b99c95654f5b36c2904b1d4806d8ebb3211.

P1 replay on this head:

• local committed HEAD = fetched refs/pr/5134 = live headRefOid = the OID above;
• PR is open against main;
• the body contains exactly one task-plan line;
• docs/plans/2026-09-28-plate-5134-main-comment-selection.md exists at this head and names only PR Keep the comment composer clear of selected text #5134;
• pnpm check and the goal-plan checker pass; focused website typecheck, registry source/changelog checks, browser geometry, and clean second autoreview pass;
• GitHub Sync auto-release checkbox check passes.

Final feedback readback before this receipt: 0 inline threads, 0 review bodies/reviews, 6 top-level comments, 0 unresolved actionable P1+.

Feedback ledger:

• Keep the comment composer clear of selected text #5134 (comment) — N/A, CodeSandbox preview only.
• Keep the comment composer clear of selected text #5134 (comment) — N/A, conditional changeset warning; registry-only app behavior uses the verified registry changelog and no published package changeset.
• Keep the comment composer clear of selected text #5134 (comment) — N/A, superseded next status report.
• Keep the comment composer clear of selected text #5134 (comment) — P1 fixed; PR targets main and exact-head ownership proof passes.
• Keep the comment composer clear of selected text #5134 (comment) — N/A, author status report independently replayed.
• Keep the comment composer clear of selected text #5134 (comment) — N/A proof receipt; quoted P1 reply read back.

No P2/P3 deferrals. No merge performed.