docs: add the empty-state illustration, completing the set

EmptyStateIllustration in both themes — Today's "nothing logged yet" state, and
the one illustration the onboarding set did not cover. Without it, onboarding
would have shipped real art while Today kept a placeholder a user sees in the
same session.

Deliberately unnumbered: it is not an onboarding step. Its ring is empty because
nothing has been logged, which is the same ring the other illustrations fill with
cycle-day markers — that is what makes the empty state read as waiting rather
than broken.

Two things recorded in dist/README.md for whoever redraws these as vectors:

- The fourteen onboarding illustrations are contained cards with a rounded
  frame; these two are full-bleed with none. The frame should be consistent
  across the set or deliberately absent from all of it.
- TodayScreen.kt calls EmptyStateIllustration(color = ..., size = ...) with a
  single colour. These are full-colour drawings, so the vector version takes no
  colour parameter and that call site changes with it.

Both were checked at the 110-160 dp the illustrations are actually drawn at, by
rendering them at that size rather than assuming: the detail survives, including
the five faint dots under the ring.

WebP at delivered resolution: 312 KB for all sixteen against 6.8 MB as PNG.

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

docs/design/dist/README.md

@@ -27,11 +27,18 @@ replace in
 | `05_PrivacyIllustration` | 5 Privacy promise | `PrivacyIllustration` |
 | `06_NotificationPrivacyIllustration` | 6 Reminder privacy | *new* |
 | `07_ForecastIllustration` | 7 First forecast | *new* |
+| `EmptyStateIllustration` | — not onboarding | `EmptyStateIllustration` |
 
 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.
 
+`EmptyStateIllustration` is the odd one and deliberately unnumbered: it is
+Today's "nothing logged yet" state, not an onboarding step, and it is also drawn
+in the onboarding previews. Its ring is empty because nothing has been logged —
+the same ring the other illustrations fill with cycle-day markers, which is what
+makes the empty state read as *waiting* rather than *broken*.
+
 ## What these got right, and why it is worth not undoing
 
 Each of these was a correction during review, and every one of them would be easy
@@ -64,13 +71,21 @@ Tracked as **#29**, which stays open until the app renders these:
 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.
+**One inconsistency to settle when these are redrawn:** the fourteen onboarding
-Onboarding would otherwise ship real art while Today keeps a placeholder visible
+illustrations are contained cards with a rounded frame, and the two
-in the same session.
+`EmptyStateIllustration` files are full-bleed with no frame. Both scale
+acceptably at the 110–160 dp these are actually drawn at — checked by rendering
+them at size rather than assumed — but the frame should be consistent across the
+set, or deliberately absent from all of it.
+
+A second, smaller one: `TodayScreen.kt` currently calls
+`EmptyStateIllustration(color = ..., size = ...)` with a single colour. These are
+full-colour drawings, so the vector version will not take a colour parameter and
+that call site changes with it.
 
 ## Format
 
-WebP at the delivered resolution — 204 KB for all fourteen, against 3.4 MB as
+WebP at the delivered resolution — 312 KB for all sixteen, against 6.8 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).