Remove sidebar header and tweak global CSS

Remove static drawer title/text from Layout.vue and refine global styles: use a color-mix-based ::selection tied to --color-primary-300 for a subtler highlight, and suppress the duplicate inner focus outline on Vuetify inputs so the field frame remains the primary focus indicator. Also update codexInfo.md to document these CSS adjustments.

GUI/src/Layout.vue

@@ -206,8 +206,6 @@ watch(
     >
       <div class="drawer-top">
         <p class="drawer-kicker">Navigation</p>
-        <h2 class="drawer-title">Dateiverwaltung</h2>
-        <p class="drawer-text">Ordner, Dateien und Ansichten schnell erreichen.</p>
       </div>
 
       <v-list nav density="comfortable" class="px-1">

GUI/src/global.css

@@ -123,7 +123,7 @@ body {
 }
 
 ::selection {
-  background-color: rgb(60 143 66 / 22%);
+  background-color: color-mix(in srgb, var(--color-primary-300) 38%, transparent);
   color: var(--color-text);
 }
 
@@ -266,6 +266,11 @@ p {
   color: var(--color-primary-600) !important;
 }
 
+/* Vuetify steuert den Fokuszustand bereits am Feld; verhindert doppelten Fokusrahmen im Input */
+.v-input .v-field :is(input, textarea, select):focus-visible {
+  outline: none !important;
+}
+
 .v-label {
   color: var(--color-text-secondary) !important;
 }