feat(theme): revise Polarized to classic green/teal dark palette

frontend/src/lib/__tests__/theme.test.ts

@@ -53,7 +53,7 @@ describe('custom themes', () => {
     expect(opt.isRounded).toBe(true);
   });
 
-  it('supports polarized and suri built-in purple dark themes', () => {
+  it('supports polarized and suri built-in dark themes', () => {
     setActiveTheme('polarized');
     expect(getActiveTheme()).toBe('polarized');
     expect(document.documentElement.getAttribute('data-theme')).toBe('polarized');

frontend/src/lib/theme.ts

@@ -70,13 +70,13 @@ export const AVAILABLE_THEMES: ThemeOption[] = [
   },
   {
     id: 'polarized',
-    name: 'Polarized (Ultraviolet)',
-    subtitle: 'Tiefdunkles Obsidian mit elektrischem Violett (0px)',
+    name: 'Polarized (Emerald / Teal)',
+    subtitle: 'Tiefdunkles Obsidian mit elektrischem Türkis/Grün (0px)',
     file: 'src/themes/theme-polarized.css',
-    previewBg: '#0d0b14',
-    previewPanel: '#151221',
-    previewAccent: '#a855f7',
-    previewText: '#f5f3ff',
+    previewBg: '#090e11',
+    previewPanel: '#10181c',
+    previewAccent: '#14b8a6',
+    previewText: '#f0fdfa',
     isRounded: false,
   },
   {

frontend/src/themes/theme-polarized.css

@@ -1,37 +1,37 @@
 /* ==========================================================================
-   MINDSIFT THEME: POLARIZED (Ultraviolet / Obsidian)
-   Tiefdunkles Obsidian mit elektrischem Violett-Akzent & scharfen Kanten.
+   MINDSIFT THEME: POLARIZED (Emerald / Teal)
+   Tiefdunkles Obsidian mit elektrischem Grün/Türkis-Akzent & scharfen Kanten.
    ========================================================================== */
 
 :root[data-theme="polarized"] {
-  /* --- 1. AKZENTFARBE (Elektrisches Ultraviolett) --- */
-  --accent-primary: #a855f7;
-  --accent-hover: #c084fc;
-  --accent-dim: rgba(168, 85, 247, 0.15);
-  --accent-border: rgba(192, 132, 252, 0.45);
+  /* --- 1. AKZENTFARBE (Elektrisches Grün / Türkis) --- */
+  --accent-primary: #14b8a6;
+  --accent-hover: #2dd4bf;
+  --accent-dim: rgba(20, 184, 166, 0.16);
+  --accent-border: rgba(45, 212, 191, 0.45);
   --text-on-accent: #ffffff;
 
   /* --- 2. OBERFLÄCHEN & HINTERGRÜNDE --- */
-  --bg-app: #0d0b14;
-  --bg-panel: #151221;
-  --bg-panel-elevated: #1d182e;
-  --bg-panel-hover: #26203c;
-  --bg-input: #0f0d18;
-  --bg-overlay: rgba(6, 4, 10, 0.78);
-  --bg-code: #08060d;
+  --bg-app: #090e11;
+  --bg-panel: #10181c;
+  --bg-panel-elevated: #162127;
+  --bg-panel-hover: #1e2c34;
+  --bg-input: #0c1317;
+  --bg-overlay: rgba(4, 7, 9, 0.78);
+  --bg-code: #070b0e;
 
   /* --- 3. TEXT & KONTRASTE --- */
-  --text-main: #f5f3ff;
-  --text-muted: #a79fc2;
-  --text-faint: #6d6585;
+  --text-main: #f0fdfa;
+  --text-muted: #8da6a9;
+  --text-faint: #5a7074;
 
   /* --- 4. RAHMEN, LINIEN & SCHATTEN --- */
-  --border-color: rgba(168, 85, 247, 0.14);
-  --border-subtle: rgba(168, 85, 247, 0.07);
-  --border-strong: rgba(192, 132, 252, 0.30);
-  --shadow-panel: 0 10px 30px rgba(5, 3, 10, 0.55);
-  --scrollbar-thumb: rgba(168, 85, 247, 0.22);
-  --scrollbar-thumb-hover: rgba(192, 132, 252, 0.40);
+  --border-color: rgba(20, 184, 166, 0.16);
+  --border-subtle: rgba(20, 184, 166, 0.08);
+  --border-strong: rgba(45, 212, 191, 0.32);
+  --shadow-panel: 0 10px 30px rgba(3, 8, 10, 0.55);
+  --scrollbar-thumb: rgba(20, 184, 166, 0.22);
+  --scrollbar-thumb-hover: rgba(45, 212, 191, 0.42);
 
   /* --- 5. STATUS- & SIGNALFARBEN --- */
   --color-success: #10b981;