feat: Vollständiges Rebranding zu MiChess, Copyright Tom Misch

- Alle @chessu/ → @michess/ (Package-Namen und Imports)
- Theme-Namen chessuDark/Light → michessDark/Light
- Alle Display-Texte: chessu/Michess → MiChess
- Autor: dotnize → Tom Misch
- Copyright: Nathaniel Tampus → Tom Misch
- README komplett neu (Deutsch, MiChess-spezifisch)
- CONTRIBUTING.md neu
- FUNDING.yml + CODE_OF_CONDUCT.md entfernt
- Fork-Hinweis auf chessu bleibt im README erhalten (MIT-Pflicht)
- pnpm-lock.yaml entfernt (wird beim Build neu generiert)

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

client/tailwind.config.js

@@ -5,12 +5,12 @@ module.exports = {
         extend: {}
     },
     plugins: [require("daisyui")],
-    darkMode: ["class", '[data-theme="chessuDark"]'],
+    darkMode: ["class", '[data-theme="michessDark"]'],
     daisyui: {
         // based on daisyUI night and winter themes
         themes: [
             {
-                chessuLight: {
+                michessLight: {
                     primary: "#047AFF",
                     secondary: "#818CF8",
                     accent: "#C148AC",
@@ -24,7 +24,7 @@ module.exports = {
                     warning: "#EFD7BB",
                     error: "#E58B8B"
                 },
-                chessuDark: {
+                michessDark: {
                     primary: "#38BDF8",
                     secondary: "#818CF8",
                     accent: "#1d4ed8",
@@ -37,6 +37,6 @@ module.exports = {
                 }
             }
         ],
-        darkTheme: "chessuDark"
+        darkTheme: "michessDark"
     }
 };