docs: onboarding illustrations, matched light and dark

Seven illustrations in a matched pair, replacing the single light-only concept
set added in 9d2a4b2. Named for the composables they replace, and identical in
dimensions per card so a theme switch swaps the image without moving the layout.

Three corrections happened during review and each is easy to reintroduce by
regenerating carelessly, so dist/README.md records them:

- No text painted into the pixels. The app renders all seven titles through
  Heading(...) already; art carrying its own title prints every heading twice,
  cannot be translated, cannot scale with font size, and is invisible to
  TalkBack.
- No step-number badge. LearningIllustration is also the Insights empty state,
  where a "4" means nothing, and baked numbers freeze a running order that has
  already changed once.
- 07_Forecast names no fields. One draft listed Fertile window and Ovulation,
  which the first-forecast screen deliberately withholds — on a fresh install it
  reports confidence Low and Today reads "Not enough history to estimate". A
  later draft named the right fields but painted "Confidence — Low"
  permanently, wrong for anyone with a settled cycle. Naming nothing is the only
  version that cannot contradict the live forecast.

The dark set is a real dark composition rather than the light one dimmed, on the
midnight-plum ground BRAND_GUIDE.md §22 specifies.

WebP at the delivered resolution: 204 KB for all fourteen against 3.4 MB as PNG.
Delivery .zip archives are gitignored; the superseded concept set is removed and
remains recoverable at 9d2a4b2.

#29 stays open — these are references, and the vectors that ship are drawn from
them.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/design/dist/.gitignore

@@ -0,0 +1,2 @@
+# Delivery archives — the extracted webp beside them is what is tracked.
+*.zip

docs/design/dist/README.md

@@ -1,55 +1,76 @@
-# Onboarding concept cards
+# Onboarding illustrations — the decided direction
 
 ```
 Status: Current
 Owner: _null
 Last reviewed: 2026-08-18
-Governs: docs/design/dist/** — the onboarding concept set and what it is for
-Review trigger: Any concept set added or replaced here; the onboarding artwork
+Governs: docs/design/dist/** — the onboarding illustration set and what it is for
+Review trigger: Any illustration added or replaced here; the onboarding artwork
                 in issue #29 landing in the app
 ```
 
-> **These are references, not assets.** Nothing in this folder ships in the APK.
-> They are the decided *direction* for onboarding, drawn from
-> [`../BRAND_GUIDE.md`](../BRAND_GUIDE.md) §22's master prompt, and the vectors
-> that eventually ship are drawn *from* them.
+> **References, not shipping assets.** Nothing in this folder goes in the APK.
+> These are the decided direction for onboarding, drawn from
+> [`../BRAND_GUIDE.md`](../BRAND_GUIDE.md) §22's master prompt. The vectors that
+> eventually ship are drawn *from* these.
 
-Seven cards, one per onboarding step, numbered to match the steps in
-`app/src/main/kotlin/dev/privacyllc/period/feature/onboarding/OnboardingScreen.kt`:
+Seven illustrations in a matched light/dark pair, named for the composables they
+replace in
+[`../../../core/designsystem/src/main/kotlin/dev/privacyllc/period/designsystem/art/Illustrations.kt`](../../../core/designsystem/src/main/kotlin/dev/privacyllc/period/designsystem/art/Illustrations.kt):
 
-| File | Step | Composable |
+| File stem | Onboarding step | Composable |
 | --- | --- | --- |
-| `onboarding-01-welcome.webp` | 1 | `Welcome` |
-| `onboarding-02-last-period-start.webp` | 2 | `LastPeriod` |
-| `onboarding-03-period-end.webp` | 3 | `PeriodEnd` |
-| `onboarding-04-previous-history.webp` | 4 | `PreviousHistory` |
-| `onboarding-05-privacy-promise.webp` | 5 | `PrivacyPromise` |
-| `onboarding-06-reminder-privacy.webp` | 6 | `NotificationPrivacyStep` |
-| `onboarding-07-first-forecast.webp` | 7 | `FirstForecast` |
+| `01_WelcomeIllustration` | 1 Welcome | `WelcomeIllustration` |
+| `02_LastPeriodIllustration` | 2 Last period start | *new* |
+| `03_PeriodEndIllustration` | 3 Period end | *new* |
+| `04_LearningIllustration` | 4 Previous history | `LearningIllustration` |
+| `05_PrivacyIllustration` | 5 Privacy promise | `PrivacyIllustration` |
+| `06_NotificationPrivacyIllustration` | 6 Reminder privacy | *new* |
+| `07_ForecastIllustration` | 7 First forecast | *new* |
 
-## Why they are not the shipping assets
+Each stem exists as `Light/<stem>_light.webp` and `Dark/<stem>_dark.webp`, at
+**identical dimensions per card**, so a theme switch swaps the image without
+moving the layout.
 
-Recorded here so nobody drops them into `res/drawable` and calls #29 done. The
-full argument, with evidence, is in the comment on that issue.
+## What these got right, and why it is worth not undoing
 
-- **They are raster.** The set is 340 KB as WebP; it was 12 MB as PNG, against a
-  1.9 MB release APK. §42 asks for Compose vector paths or `VectorDrawable`.
-- **The titles and subtitles are painted into the pixels**, and the app already
-  renders all seven itself through `Heading(...)`. Used as-is, every title
-  appears twice — and baked text cannot be translated, cannot scale with the
-  user's font size, and is invisible to TalkBack.
-- **They are light mode only.** `BRAND_GUIDE.md` §22 names the dark palette, and
-  [`../README.md`](../README.md) requires a light/dark preview pair per screen.
-  A vector set recolours from theme tokens; a raster set has to be drawn twice.
-- **Card 7 shows a fertile window and ovulation**, which the first-forecast
-  screen deliberately does not — on a fresh install it shows confidence Low and
-  Today reads "Not enough history to estimate". That conflict is a product
-  decision to settle before anything is drawn, not a detail to fix in the art.
+Each of these was a correction during review, and every one of them would be easy
+to reintroduce by regenerating carelessly:
 
-## Provenance and format
+- **No text of any kind is painted into the pixels.** The app renders all seven
+  titles and subtitles itself through `Heading(...)` in `OnboardingScreen.kt`.
+  Art carrying its own title prints every heading twice, cannot be translated,
+  cannot scale with the user's font size, and is invisible to TalkBack.
+- **No step-number badge.** `LearningIllustration` is not only onboarding step 4
+  — it is also the Insights empty state, where a "4" means nothing. Baked numbers
+  also freeze the running order, and this flow has already changed shape once. A
+  step indicator, if wanted, belongs in live UI where TalkBack can read it.
+- **`07_Forecast` shows a calendar and a cycle arc, and names no fields.** An
+  earlier draft drew a forecast panel listing *Fertile window* and *Ovulation*,
+  which the real first-forecast screen deliberately does not show — on a fresh
+  install it reports confidence Low and Today reads "Not enough history to
+  estimate". A later draft named the correct fields but painted *Confidence —
+  Low* permanently, which is wrong for anyone with a settled cycle. Naming
+  nothing is the only version that cannot contradict the live forecast.
+- **The dark set is a real dark composition**, not the light one dimmed — the
+  midnight-plum ground `BRAND_GUIDE.md` §22 specifies.
 
-Generated from `BRAND_GUIDE.md` §22's master prompt, which is the workflow that
-section exists to describe. Converted from the delivered PNGs to WebP at their
-original 1086×1448 — same resolution, about a fortieth of the bytes, and the
-same format [`../../data/img/`](../../data/img/) already uses for the marks
-privacyllc.dev renders.
+## Still to do before anything ships
+
+Tracked as **#29**, which stays open until the app renders these:
+
+1. Redraw as Compose vector paths behind the existing replaceable names, taking
+   colour from theme tokens rather than shipping two raster sets.
+2. Add the light/dark preview pair per step, per [`../README.md`](../README.md).
+3. Reconcile step copy — `PRODUCT_PLAN.md` owns the screen wording.
+
+`EmptyStateIllustration`, the Today "nothing logged yet" state, has no card here.
+Onboarding would otherwise ship real art while Today keeps a placeholder visible
+in the same session.
+
+## Format
+
+WebP at the delivered resolution — 204 KB for all fourteen, against 3.4 MB as
+PNG, and the same format [`../../data/img/`](../../data/img/) uses for the marks
+privacyllc.dev renders. The delivery `.zip` archives are deliberately not
+tracked; see [`.gitignore`](.gitignore).