Add a standing manual-verification QA checklist for what tests can't cover

CLAUDE.md

@@ -20,6 +20,8 @@ See @AGENTS.md for project overview, architecture rules, and the AI developer pr
 - **[docs/IMPLEMENTATION-PLAN.md](docs/IMPLEMENTATION-PLAN.md)** — incremental milestone
   plan (M0–M6), MVP boundary, per-milestone tests + manual checks, and an architecture
   reference index.
+- **[docs/manual-verification.md](docs/manual-verification.md)** — standing QA checklist for
+  what tests can't cover (offline/install, keyboard/a11y, theming, reduced-motion).
 - **[AGENTS.md](AGENTS.md)** — onboarding, stack, directory map, scripts, conventions.
 
 ## Quick Orientation

docs/manual-verification.md

@@ -0,0 +1,50 @@
+# Manual Verification Checklist
+
+> A standing memo, **not** a milestone. These are the things automated tests can't
+> cover — they need a real browser, a real install, or a human eye. Run the relevant
+> sections before a release, or after any change to the app shell, PWA config,
+> routing, theming, or focus/keyboard behavior. Tests stay green ≠ these pass.
+
+## Offline & installable (PWA)
+
+- [ ] First load online, then go offline (DevTools → Network → Offline) and reload —
+      the app boots, fonts render (no system-font fallback), a previously-opened
+      snippet still renders.
+- [ ] Install as a standalone app (desktop install button / Android "Add to Home
+      screen") — it installs, launches in its own window, and shows the astrolabe
+      icon (not a generic glyph).
+- [ ] Android adaptive icon (maskable) fills the OS shape without clipping the mark.
+- [ ] Service-worker update flow: ship a new build, reload — the update-available
+      prompt appears and applying it loads the new version (`registerType: 'prompt'`).
+- [ ] iOS home-screen icon — **known residual**: the manifest ships SVG only; iOS
+      wants a PNG `apple-touch-icon`, so the iOS home-screen icon may fall back.
+
+## Keyboard & accessibility
+
+- [ ] Full keyboard-only run-through: create/select/edit a snippet, open and dismiss
+      each modal, drive the pane toggle strip and both resize handles, reach Datasets.
+- [ ] Focus is never orphaned or trapped: modals trap focus and return it to the
+      opener on close; hiding a pane from the strip keeps focus on the toggle.
+- [ ] Visible focus ring on every interactive control, in both themes.
+- [ ] Text and UI contrast pass AA in light and dark.
+
+## Routing & view-state
+
+- [ ] Reload restores the view from the URL hash (`#snippet-<id>`, `#datasets/…`).
+- [ ] Browser Back/Forward moves through view-state as expected.
+
+## Theming
+
+- [ ] Light⇄dark flip repaints the whole app — chrome, Monaco, and the chart.
+- [ ] No placeholder styling or raw hexes leak through on any surface.
+
+## Reduced motion & feedback
+
+- [ ] With `prefers-reduced-motion`, toasts and transitions honor it (no large motion).
+- [ ] Toasts stack, auto-dismiss, and fade as specified; the live-preview busy
+      indicator appears for slow (>~1s) renders and clears after.
+
+## Visual sweep of the M6 surfaces
+
+- [ ] Library search / sort / empty states, the storage monitor, About & Donate
+      modals, and the busy indicator all look deliberate and behave per spec.