Release Checklist: Dark Mode Toggle v1.4.0

Date: 2026-06-19 Plan: prd.md Go / No-Go: GO Deployed by: Notes web team Blocking items: none

Produced by release-checklist from tasks.md and prd.md.

Stage 1: Pre-Release Gates

Task Completion

All P0 tasks are [x] complete (none in [ ], [~], or [!])
No [-] skipped tasks to confirm (none were skipped)
No tasks are [~] in progress

Task state confirmed with python3 ../../skills/_shared/scripts/plan-metrics.py tasks.md and plan-validate.py tasks.md: 11/11 complete, 0 in-progress, no validation flags.

Quality Gates

bun run check passes
bun run format passes
bun run lint passes
bun run test passes (42 tests, 100% passing)
bun run build passes (build output: dist/)

PRD Success Criteria

Switch themes in one interaction — verified by: integration test + manual smoke
Persists across reloads/sessions — verified by: persistence test (Task 1.7)
No flash of wrong theme — verified by: FR-5 regression test (Task 2.3) + manual on fresh profile
OS default on first visit — verified by: resolveTheme unit tests + manual on a dark-set OS
Dark theme meets WCAG AA contrast — verified by: contrast audit (Task 2.2)

Stage 2: Deployment Prerequisites

Environment Variables

None introduced by this release.

Database Migrations

None — the feature is client-only.

Feature Flags

None — shipping on for all users (additive, defaults to current OS theme).

External Services

None added.

Stage 3: Deployment Steps

1. Tag the release: git tag v1.4.0 && git push --tags
2. Deploy the static build: bun run build then publish dist/ via the existing CI deploy
3. Confirm the deployment is live: load the app and check the build hash
4. Invalidate the CDN cache for index.html (the inline theme script changed)

Stage 4: Smoke Tests

New Features (from this release)

Toggle to dark — Steps: click the toggle — Expected: UI switches immediately to dark
Persistence — Steps: toggle dark, reload — Expected: still dark, no flash
OS default — Steps: clear storage on an OS set to dark, load — Expected: app renders dark

Existing Critical Paths (regression check)

Create a note — Steps: open editor, type, save — Expected: note saved, readable in both themes
Search — Steps: search a known note — Expected: results render correctly in the active theme

Stage 5: Rollback Plan

Decision criteria: Roll back if:

Any client error rate exceeds baseline +1% within 30 minutes of deploy
A P0 smoke test fails and cannot be fixed within 30 minutes
The theme script breaks first paint on a supported browser

Rollback steps:

Re-publish the previous build artifact (tag v1.3.x)
Invalidate the CDN cache for index.html
Notify the team in the release channel

Time to rollback: Estimated < 10 minutes. No data migration, so rollback is clean.

Stage 6: Post-Release Verification

Client error rate is at baseline (check: error tracker)
No spike in console errors referencing localStorage or data-theme (check: log aggregator)
Theme toggle works on the top 3 supported browsers (manual)
Notify the team that v1.4.0 is live

Changelog Entry (for `CHANGELOG.md`)

## [1.4.0] — 2026-06-19

### Added
- **Dark mode.** Notes now has a light and dark theme with a toggle on every
  page. Your choice is remembered on this device, and if you haven't picked one,
  Notes follows your system's appearance setting. The page no longer flashes the
  wrong colors while loading, and the dark theme meets WCAG AA contrast.