feat(ui): Beta-Badge in Login-, Dashboard- und Logbuch-Titelzeile

Wiederverwendbare BetaBadge-Komponente mit i18n-Tooltip.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/App.css

@@ -63,6 +63,16 @@ body {
   margin-bottom: 15px;
 }
 
+.auth-brand-title-row {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  justify-content: center;
+  gap: 10px;
+  margin-bottom: 14px;
+}
+
+.auth-brand-title-row h1,
 .auth-brand h1 {
   font-size: 32px;
   font-weight: 700;
@@ -71,7 +81,7 @@ body {
   -webkit-background-clip: text;
   background-clip: text;
   -webkit-text-fill-color: transparent;
-  margin: 0 0 14px 0;
+  margin: 0;
   line-height: 1.25;
   letter-spacing: -0.5px;
 }
@@ -3191,6 +3201,28 @@ html.theme-cupertino .events-scroll-container {
   border: 1px solid rgba(251, 191, 36, 0.25);
 }
 
+.beta-badge {
+  display: inline-flex;
+  align-items: center;
+  padding: 2px 8px;
+  border-radius: 999px;
+  font-size: 11px;
+  font-weight: 600;
+  letter-spacing: 0.04em;
+  text-transform: uppercase;
+  color: var(--app-accent-light);
+  background: var(--app-accent-bg);
+  border: 1px solid var(--app-accent-focus-ring);
+  flex-shrink: 0;
+}
+
+.header-brand-title-row {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 10px;
+}
+
 .role-badge {
   display: inline-flex;
   align-items: center;