feat(web): edit and number chat annotations

[darox]

Note

Stacked on pingdotgg/t3code#5224. This PR contains exactly one follow-up commit; review the changes relative to codex/chat-annotations-desktop.

What Changed

Adds editing and numbered indicators to the response-text annotations introduced in pingdotgg#5224.

Users can now:

• See numbered markers beside annotated assistant text.
• Distinguish plain selections from selections with comments.
• Click a marker to highlight the source text and edit or delete pending annotations.
• Keep multiple annotations tied to their exact source ranges while reviewing them in the composer.

Why

The base annotation flow makes it possible to attach selected response text, but pending annotations are difficult to locate again and cannot be corrected without removing and recreating them. Numbered markers make the relationship between the composer summary and assistant response obvious, while the editor keeps small comment changes fast.

UI Changes

Before

The base flow exposes selection and composer actions, but does not show numbered source markers or an edit affordance.

After

Selecting response text still opens the existing Add to chat action.

Pending annotations now show numbered markers beside the source response and a matching composer summary.

Clicking a marker highlights the source text and opens an editor for the comment.

Multiple annotations receive stable sequential numbers and remain visible alongside the prompt.

After sending, the conversation keeps the compact annotation summary without exposing serialized markup.

Validation

• ./node_modules/.bin/vp test run apps/web/src/chatSelectionAnnotation.test.ts apps/web/src/components/ChatView.logic.test.ts apps/web/src/components/chat/MessagesTimeline.test.tsx apps/web/src/composerDraftStore.test.ts apps/web/src/proposedPlan.test.ts (158 passed)
• ./node_modules/.bin/vp run --filter @t3tools/web typecheck
• ./node_modules/.bin/vp run --filter @t3tools/shared typecheck
• git diff --check
• Manual verification in an isolated local T3 environment: selection popover, optional comment entry, numbered markers, edit/delete editor, multiple annotations, and sent summary.

Checklist

• This PR is explicitly stacked on feat(web): attach selected response text pingdotgg/t3code#5224
• This PR contains one follow-up commit
• I explained what changed and why
• I included before/after screenshots for the UI changes
• I included interaction coverage in the validation notes

Model: OpenAI Codex · Harness: Codex desktop