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>

frontend/tailwind.config.js

@@ -1,3 +1,4 @@
+import animate from 'tailwindcss-animate';
 // Theme colours are CSS variables, so Tailwind cannot apply opacity modifiers (bg-accent/15) by itself.
 // v() mixes the variable with transparent for a modifier; plain classes keep the bare variable, so only
 // the tints depend on color-mix() support.
@@ -98,5 +99,6 @@ export default {
       },
     },
   },
-  plugins: [],
+  // animate-in / fade-in / slide-in-from-* / zoom-in-* used by menus, sheets and dialogs
+  plugins: [animate],
 };