feat(canvas): add Leave feedback survey modal to Channels view

[raquelmsmith]

Summary

Adds a "Leave feedback" button next to "Go back to Code" in the project-bluebird Channels title bar, and routes "Go back to Code" through the same modal first.

1. Leave feedback → opens a modal with a text box; submitting records the text as a PostHog survey response.
2. Go back to Code → opens the same modal as a gentle intercept. The user can Skip (the secondary button reads "Skip" only in this flow; it reads "Cancel" when opened via "Leave feedback"). After submit or skip, the user is routed back to /code. In the "Leave feedback" flow, submit/cancel just closes — no navigation.

How it works

• Survey responses are sent via posthog-js's "survey sent" event, routed through the existing AnalyticsTracker seam (new captureSurveyResponse method) so feature code never imports posthog-js directly.
• The backing survey is an api-type single-open-question survey created + launched in PostHog. Its IDs are stored in packages/ui/src/features/canvas/feedbackSurvey.ts:
  • Survey: 019ee235-2e3b-0000-64b3-5f2efa487452 (us.posthog.com project 2)

Files

• features/canvas/components/FeedbackModal.tsx (new) — quill Dialog + Radix TextArea; Skip/Cancel labeling driven by mode; submit disabled until text entered.
• features/canvas/feedbackSurvey.ts (new) — survey/question ID constants.
• shell/analytics.ts + shell/posthogAnalyticsImpl.ts — captureSurveyResponse on the analytics tracker.
• router/routes/__root.tsx — buttons + modal wiring in the channels branch.
• apps/web/src/web-container.ts — no-op captureSurveyResponse for the web stub tracker.

⚠️ Note on the survey project

The survey lives in us.posthog.com project 2, but the desktop app's analytics host is build-time configured (VITE_POSTHOG_API_HOST, default internal-c.posthog.com). survey sent events only attach to this survey if the running build reports to project 2. Confirm via surveys-responses-list once a build pointed there exercises the flow.

Test plan

• @posthog/ui, @posthog/web, @posthog/code typecheck
• Biome lint clean on all touched files (no noRestrictedImports violations)
• New FeedbackModal.test.tsx (5 tests) + existing posthogAnalyticsImpl tests (11) pass
• Manual: in /website, both buttons render; "Leave feedback" shows Cancel and stays on Channels; "Go back to Code" shows Skip and routes to /code on submit/skip

🤖 Generated with Claude Code

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit 69da6e9.}

[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
packages/ui/src/features/canvas/components/FeedbackModal.test.tsx:27-45
**Two similar mode/button-label tests could be parameterised**

The two tests that verify which secondary button label appears are structurally identical and differ only in their `mode`, `expectedButton`, and `missingButton` values. The team's convention is to prefer parameterised tests. Merging them into a single `it.each` would remove the duplication without losing any coverage.

_{Reviews (1): Last reviewed commit: "feat(canvas): add Leave feedback survey ..." | Re-trigger Greptile}

[greptile-apps]

_{Reviews (2): Last reviewed commit: "style(canvas): wrap FeedbackModal JSX to..." | Re-trigger Greptile}