fix(web): an unsaved citation comment survives a provider question - #13336

Fixes #13334.

Problem

The text of a citation comment lives only in AssistantCitationCommentEditor's local state until it is saved or the popover is dismissed (#10831). When a provider question arrives, ChatComposer reuses the prompt editor for the answer: its value switches from the prompt to the pending answer, the controlled-value effect calls setContent, the whole document is replaced, and the citation's node view (with its popover and editor) unmounts. No dismissal fires, so nothing is settled and the draft is lost; once the question is answered the citation is back without the comment. An approval request takes the same editor.

Direction

This follows the triage on #13334: "Committing the draft into the prompt before setContent, the same commit #10831 already does on dismissal, would put the comment on the chip that comes back." An earlier version of this PR only kept the draft for the next time the pencil was opened, which the triage pointed out leaves the chip without the comment and Send without it. That is replaced by the commit below.

Fix

• The unsaved text is kept outside the node view as the reader types: assistantCitationCommentDrafts.ts is a small in-memory map keyed by the composer it belongs to, the serialized citation and its order among identical citations (assistantCitationDraftKey). The node's citeKey cannot be the key, because the composer rebuilds its document from the prompt text and assigns fresh random keys on every value change.
• When a question or an approval borrows the prompt editor, ChatComposer calls commitAssistantCitationCommentDrafts, which writes each of that composer's drafts onto its citation in the prompt text through the same rules a dismissal uses (resolveAssistantCitationCommentDismissal). The chip comes back carrying the comment and Send includes it, with no need to reopen the pencil.
• A draft those rules would not commit, one over the length limit, stays a draft and is resumed when its popover is opened again, so nothing typed is dropped.
• Sending the prompt takes every draft its composer still holds, so a leftover cannot surface on the next prompt that cites the same text; the ordinary, plan follow-up and multiple-model failure handlers give them back together with the prompt.

The prompt editor stays shared with the answer input, as before.

Tests

assistantCitationCommentDrafts.test.ts covers the commit: a draft is written onto its citation and removed, it replaces a different saved comment, a draft equal to the saved comment or over the length limit leaves the prompt unchanged (the latter stays in the store), identical citations get their own comments by their original order, another composer's drafts are neither applied nor removed, and prompts without drafts or citations come back unchanged. It also pins the key (stable for the same citation, distinct by order and across composers) and that a send takes only its own composer's drafts and a failed send gets them back. AssistantCitationChip.test.tsx covers resuming a draft when the chip mounts again and forgetting it after Save and Cancel. 21 tests pass across the two files; web typecheck, lint, formatter and knip are clean.

Evidence

Captured on the orchestrator V2 base in the web client on macOS 15.7.5, using Playwright headless Chromium 1400×900 and light appearance. Before is main after the V2 merge, at e9298af (this branch's merge base); after is this branch at b2d89de. Both servers used fresh isolated state and the same synthetic project.

A local Claude stand-in emitted Evidence fixture message for citations. and waited until the unsaved draft was typed before issuing AskUserQuestion with “Proceed?” and Yes/No. No provider account or model call was used. I selected fixture message for citations by mouse, cited it into the composer, opened the pencil and typed unsaved comment typed before the question without saving. Then I answered Yes, checked the returned chip before touching the pencil, reopened and closed the popover unchanged, and sent the prompt asking for the quoted comment back. No DOM/state injection or clock mocking was used.

	before (V2 main base @ e9298af)	after (PR @ b2d89de)
typed, unsaved, before the question
composer back on the prompt, pencil not touched
popover reopened
sent message

Recordings, about 11 seconds each at normal speed: before.mp4, after.mp4. GIF copies: before.gif, after.gif.

Observed: on the V2 main base the returned chip shows only the quote, the reopened popover is empty, and the sent citation carries no comment. On this branch the returned chip already shows the comment, the reopened popover contains all 41 characters, and the sent citation carries the exact comment. The stand-in parses the received citation and echoes the quote before the fix and unsaved comment typed before the question after it. This verifies the submitted payload without a real model call.

Not exercised in the client: the approval path, an over-limit draft, failed-send recovery, the desktop shell, mobile, other providers, and remote/tunnel connections.

Implemented with Claude Code (Claude Fable 5.1); tests written with Codex (GPT-6 Astra).