feat(desktop): split model switch and session summary

[puemos]

Problem

A person who changes the model mid-session can get stuck in the dialog. Pressing "Copy summary" starts an AI turn that takes about 35 seconds, and while it runs the dialog disables Cancel and Switch now, and ignores Esc.

• One dialog carries three jobs: the cache cost, the model change, and handing work to another agent.
• "Copy summary" reads as a clipboard action, so nothing warns that a long job starts.
• The progress and the result appear in the side-question card, which sits behind the modal that started them.
• The card titles itself with the raw internal prompt, and nothing clears it when the switch ends.

Changes

Before	After

The before shot is a Storybook render of the dialog on master. The after shot is the running app.

• The dialog asks one question: the models, the cost to resend history, then Cancel or Switch model.
• Esc and Cancel stay live. Only the switch request holds the dialog, and it resolves in about a second.
• The task overflow menu gains "Summarize for another agent", which works whether or not a model changes.
• The summary lands in its own panel above the composer. It reports the wait, then offers Copy and Dismiss.
• The panel says "Writing the summary. About 30 seconds." while it runs, because the wait surprised people.
• "Stop waiting" drops the summary. The panel says the agent still finishes the turn, because nothing can cancel it.
• The dialog no longer requests the task's cost so far. The context indicator beside the model selector already shows it.

Note

The dialog no longer says that a switch keeps the same environment, files and permissions. That line was reviewed and cut as clutter, so the belief that a model switch restarts a task stays uncorrected in the product.

Mechanical: the side-question store gains a kind, a label and an askedAt, so one store can back two surfaces. SideQuestionCard drops its Radix imports. The panel splits into a container and a view, which is what makes the view storyable.

How did you test this code?

The person driving this work ran the desktop app and exercised the dialog and the panel. This agent did not run the app.

Automated, by this agent:

• SessionSummaryPanel.test.tsx is new. It catches a panel that renders for a prior task run, and a dismiss that leaves the entry in the store.
• SideQuestionCard.test.tsx gains one case: a summary entry must render nothing in the /btw card. Without it, both surfaces would show the same answer.
• ModelSwitchCacheDialog.test.tsx loses the task-cost cases with the feature, and follows the renamed button.
• Storybook stories cover the panel's writing, written, long and failed states, and the dialog's four pricing cases.

Not checked: every desktop suite outside features/sessions, and the e2e suite. CI reports those.

Automatic notifications

• Publish to changelog?

Docs update

None. No documented workflow changes.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Claude Code (Opus 5) in PostHog Desktop, directed step by step over one session.

Skills invoked: /writing-tests, /writing-pr-descriptions, /writing-user-facing-copy, /writing-code-comments, posthog:building-html-canvases, posthog:validating-and-publishing-canvases.

Decisions across the session:

• An abort path for the summary was planned and dropped. The agent protocol has no cancel for a side question, so a "Stop" that claimed to abort would have been false.
• The task's cost so far first got a skeleton row to stop a layout jump, then came out entirely once the duplicate on the context indicator was confirmed.
• The dialog's facts row went through pills and a single-line layout. Both failed: quill Badge is a 10px scale, which made the model names the smallest text in the dialog, and the one-line version wrapped and stranded the price at the real dialog width.
• Related open PR: fix(desktop): stop offering a handoff summary on a finished cloud run #95056 hardens sessionSupportsSideQuestion for finished cloud runs. It touches no file in this PR, and the new menu item consumes that same guard.

Public artifact: this work started from a report of one person's session. No part of that material reaches this PR. The screenshots show the agent's own test session, the sample summary in the Storybook story is invented, and no customer data, ticket or log is quoted.

[trunk-io]

😎 Merged successfully - details.

[github-actions]

React Doctor found 3 issues in 2 files · 3 warnings.

3 warnings

packages/ui/src/features/sessions/components/ModelSwitchCacheDialog.tsx

• ⚠️ packages/ui/src/features/sessions/components/ModelSwitchCacheDialog.tsx:61 All state reset on prop change no-reset-all-state-on-prop-change
• ⚠️ packages/ui/src/features/sessions/components/ModelSwitchCacheDialog.tsx:64 State adjusted after a prop changes no-adjust-state-on-prop-change

packages/ui/src/features/sessions/components/SessionView.tsx

• ⚠️ packages/ui/src/features/sessions/components/SessionView.tsx:104 Non-component export in component file only-export-components

_{Reviewed by React Doctor for commit a6bd604.}

[github-actions]

🤖 CI report

✅ Trunk lane — non-backend lane (fe:product:desktop)

This PR is assigned to the non-backend lane (fe:product:desktop). It does not run backend Python tests and may merge in parallel with PRs in other lanes.

[hosthog]

HostHog preview — posthog-desktop-web

The previews for this PR have been torn down and no longer serve.

[stamphog]

Approved.

Contained desktop UI refactor by an owning-team author with no touches to auth, billing, data models, public APIs, or CI/build tooling; tests were updated/added for the new components and no unresolved review concerns exist.

• Author wrote 66% of the modified lines and has 49 merged PRs in these paths (familiarity MODERATE).
• 14 of the 14 changed files are governed by products/desktop/AGENT_APPROVALS.md.

Gate mechanics and policy version

Gate		Result
prerequisites	✓	all clear
deny-list	✓	no deny categories matched
size	✓	684L, 11F substantive, 838L/14F incl. docs/generated/snapshots — within ceiling
tier	✓	T1-agent / T1d-complex (838L, 14F, single-area, feat)
stamphog 2.0.0b4		.stamphog/policy.yml @ a6bd604 · reviewed head a6bd604

[puemos]

/trunk merge

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-09-07 13:35 UTC	Run
prod-us	✅ Deployed	2026-09-07 13:48 UTC	Run
prod-eu	✅ Deployed	2026-09-07 13:50 UTC	Run