feat(ui): Terrakotta Nacht replaces Soft, smooth menus and sliding notes on phones

- dark counterpart of Terrakotta; Soft users move to it
- add tailwindcss-animate: the existing animate-in/fade/slide classes now
  run; menus zoom in, sheets slide up, notes slide in on phones
- no animations with reduced motion

chore(release): v0.13.0

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Doku/theming.md

@@ -81,7 +81,7 @@ Jede Theme-Datei gliedert sich in sechs exakt definierte Bereiche:
 | `dark` | [`theme-dark.css`](../frontend/src/themes/theme-dark.css) | Standard Dark Slate / Monochrom | Streng eckig (`0px` Cards, `2px` Buttons) |
 | `light` | [`theme-light.css`](../frontend/src/themes/theme-light.css) | Daylight Clean White / Minimalistisch | Modern dezent (`4px` Cards, `4px` Buttons) |
 | `terracotta` | [`theme-terracotta.css`](../frontend/src/themes/theme-terracotta.css) | Warmes Cremepapier, Tinte, Terrakotta-Akzent, eigene Code-Farben in Erdtönen | Weich (`12px`) |
-| `soft` | [`theme-soft.css`](../frontend/src/themes/theme-soft.css) | Warmes Soft Slate mit Indigo-Akzent | Weich gerundet (`12px` Cards, `8px` Buttons) |
+| `terracotta-night` | [`theme-terracotta-night.css`](../frontend/src/themes/theme-terracotta-night.css) | Espresso-Braun, Creme-Schrift, glühender Terrakotta-Akzent | Weich (`12px`) |
 | `polarized` | [`theme-polarized.css`](../frontend/src/themes/theme-polarized.css) | Tiefdunkles Obsidian mit elektrischem Grün/Türkis | Streng eckig (`0px` Cards, `2px` Buttons) |
 | `suri` | [`theme-suri.css`](../frontend/src/themes/theme-suri.css) | Warmes Mitternachts-Pflaume mit samtiger Orchidee | Weich gerundet (`10px` Cards, `6px` Buttons) |
 | *Template* | [`theme-template.css`](../frontend/src/themes/theme-template.css) | Vollständig dokumentierte Kopiervorlage | Frei anpassbar |