polish: align back cover prompt with front cover design language

- Added same style references (Folio Society, Edmund Dulac, Efteling, Ghibli)
- Matched color vocabulary: prussian blue, jewel tones (sapphire/amethyst/
  emerald/rose gold), warm amber/gold
- Added same quality descriptors: visible brushwork, ink linework, paper grain
- Fixed 12 vignettes: added Story 3 loom, removed duplicate Story 1 owl
- Clarified lower-half text-clear zone

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

DOSSIER.md

@@ -1010,35 +1010,40 @@ Aspect ratio 1:1. No text, no borders, no frames.
 > Komposition, keine dichten Details in der Bildmitte (wo der Klappentext steht).
 
 ```
-A dreamy, atmospheric children's book endpaper illustration in soft watercolor and
-gouache. Square composition, intended as a translucent background layer.
+A children's book endpaper illustration in the style of a Folio Society luxury
+edition, painted in luminous watercolor and gouache with fine ink linework.
+Square composition, intended as a translucent background layer at reduced opacity.
 
-Wide, sparse composition: a deep midnight blue sky fills most of the image.
-Scattered across it — small, luminous vignettes from twelve fairy tale worlds,
-arranged loosely like constellations rather than crowded together. Each vignette
-is a tiny glowing island of detail floating in the dark:
+Wide, sparse composition: a vast deep prussian blue night sky fills the image.
+Scattered across it — twelve tiny luminous vignettes, one from each fairy tale
+world, arranged loosely like constellations floating in the dark:
 
-A glass tree with silver leaves. A teacup adrift on a river of starlight.
-A friendly red dragon breathing soap bubbles. A moth with iridescent wings.
-A clockwork gear made of chocolate. A unicorn's silver mane. A wise owl on a
-branch. A lantern glowing gold. A flying book trailing sparks. A sleeping giant
-with moss on his chest. A dandelion carrying a boy into the stars. A ship
-sailing through clouds.
+A glass tree with silver leaves. A sailing ship riding silver clouds.
+A loom hung with threads of living light. A tiny ruby-red dragon breathing
+iridescent soap bubbles. A dandelion seed drifting beside a tiny fallen star.
+A flying book trailing emerald sparks. A silver unicorn's mane flowing in
+starlight. A chocolate clockwork gear catching amber light. A moth with
+cathedral stained-glass wings. A sleeping giant with wildflowers grown on his
+chest. A porcelain teacup adrift on a river of starlight. A paper lantern
+glowing warm gold.
 
-The vignettes are small and delicate — they should feel like glowing embers in a
-dark sky, not a busy scene. Large empty areas of deep prussian blue and midnight
-indigo between them, soft and restful.
+Each vignette is small, self-contained and radiant — a glowing ember floating
+in the dark, not a crowded scene. Deep empty expanses of prussian blue and
+midnight indigo between them, soft and restful.
 
-In the lower third of the image, a faint luminous mist settles — leaving the
-center and bottom largely clear for overlaid text.
+The lower half of the image fades into clear dark sky, leaving ample space
+for overlaid text.
 
-Color palette: deep prussian blue, midnight indigo, very dark navy, with warm
-amber and pale gold accents on each glowing vignette. No bright backgrounds, no
-light areas except the tiny illuminated motifs themselves.
+Color palette: deep prussian blue and midnight indigo throughout, with
+jewel-tone accents on each vignette — sapphire, amethyst, emerald, rose gold —
+mirroring the front cover palette exactly. Warm amber and soft gold on the
+glowing motifs.
 
-Style: loose, painterly watercolor washes. Folio Society / fairy tale annual
-aesthetic. Visible paper grain, soft edges, ink so fine it disappears into the
-dark. Quiet, poetic, unhurried.
+Style: painterly, hand-crafted, no photorealism. Inspired by Efteling
+illustration, Studio Ghibli background art, and Edmund Dulac fairy tale
+paintings. Rich texture, visible brushwork, delicate ink outlines, subtle
+paper grain. Warm and mysterious, inviting and slightly magical.
+Premium print quality, high detail.
 
 Aspect ratio 1:1. No text, no borders, no frames.
 ```