feat(APP-1004): iterate the support assistant on design feedback

[tyhonchik]

This reworks the support assistant panel along Evan's design review. The widget shipped as a straight port of the assistant-ui registry thread: a generic header, a ticket card that led with a "Review your request" label, the request history parked on the greeting screen, and a mail button competing for space in the header. Now the header carries the Aragon mark and a live subline naming what the conversation is working on, the card leads with the ticket itself, and past requests get a view of their own. The spec is the Claude Design project Aragon Support Assistant.dc.html plus the divergence list in its github.md.

Changes

• Header names the object, not only the panel. Title is Aragon Assistant, with a subline underneath: New conversation on a fresh chat, Draft: Clicking any button in the app causes a crash while the model assembles a draft, SUP-123: … once it is filed. It reads the last createLinearTicket part in the thread, so it follows the ticket with no extra state.
• Ticket card leads with the ticket. The Review your request heading and the intent tag are gone, the drafted title is the card's heading, the description renders plain with no Details micro-label, Steps to reproduce is body weight over a numbered list, and the contact reads as a sentence: We'll reply to evan@aragon.org. Actions sit behind a divider as Create ticket / Dismiss.
• Spent drafts stop being cards. Superseded, dismissed and interrupted drafts collapse into one centered grey line in the transcript instead of an empty bordered box.
• Past requests move off the greeting. A quiet Past requests (2) link under the composer opens a list view with a back chevron in the header. The composer is hidden there because it lives inside the thread that the view replaces. Link and list read through one useRequestHistory hook.
• One quiet line under the composer. On a fresh chat it is the past-requests link; in a conversation it is Prefer a human? Email support. The header mail button is dropped, so that escape hatch has a single home.
• Time dividers. A divider opens the transcript and marks a resumed conversation (Today 14:26, Monday 09:41), fired when the pause between two messages passes 30 minutes.
• Panel owns its own dismissal. The header close button became a collapse chevron pointing at the panel edge, and SupportChatTrigger withdraws from the navigation bar while the panel is open instead of doubling as the close control.
• Smaller things: the composer placeholder switches between Describe the issue… and Reply…, the greeting is now What do you need help with?, the user bubble grew a tail, the composer sits on white with a neutral-200 border, the tool name comes from createTicketToolName rather than a literal, and the unused trigger.close locale key is gone.

Note

The design shows a transcript spanning days (Monday 09:41 next to Today 14:26), which cannot happen yet: the session is in-memory, so a reload starts an empty chat. Dividers are therefore gap-based and session-only, and in practice you see exactly one, above the first message. I left transcript persistence out of this PR.

The Aragon mark lives in the widget as its own component, because the package must not import from apps/app and gov-ui-kit ships no logo at ^2.9.0. It is a copy of aragonLogoIcon.tsx, worth collapsing if the kit ever gains one.

The collapse chevron is the same at every breakpoint, including the fullscreen drawer below lg, where an X would read a little better.

[linear-code]

APP-1004

[github-actions]

🚀 Preview Deployment: View Here

[github-actions]

E2E results (preview)

Smoke

Base URL	https://app-next-qykvjrvzh-aragon-app.vercel.app
Suite	smoke
Playwright result	❌ failed
Summary	81 passed, 1 failed
HTML report	View report
GitHub job	✅ completed

View run #4858