Theme "Tintenblau" (dark and light)

Palette from the Tintenblau desktop theme (colors.toml, neovim.lua, zed.json):
ink blue with cream text, paper with dark ink. Also in the terminal client's
palettes.

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

web/src/whatsnew.ts

@@ -3,6 +3,10 @@
  * under "unreleased"; scripts/release.sh renames the key to the release version.
  */
 export const WHATS_NEW: Record<string, { en: string[]; de: string[] }> = {
+  unreleased: {
+    en: ["New theme “Tintenblau” (Settings → General → Theme)"],
+    de: ["Neues Theme „Tintenblau“ (Einstellungen → Allgemein → Theme)"],
+  },
   "202611-00021": {
     en: ["Git commits of agents name the model: “Co-Authored-By: <model> (<provider>) via CodeCraft” (Settings → General)"],
     de: ["Git-Commits von Agenten nennen das Modell: „Co-Authored-By: <Modell> (<Anbieter>) via CodeCraft“ (Einstellungen → Allgemein)"],