feat(admin): add orange rgb(241,119,50) as an exact brand-color option

Revert the earlier mis-scoped orange on the personalization panel and
instead expose rgb(241,119,50) as a selectable 'رنگ اصلی' swatch. When
picked it overrides --primary/-600/-700/-soft/-soft2/-ring inline with
exact hex, so every var(--primary) consumer across the whole admin
(buttons, active nav, rings) becomes that orange. Non-fixed hues keep
the oklch hue pipeline (inline overrides removed on switch).

- uiStore: BrandHue interface + optional fixed hex; shared applyBrand()
  helper handles fixed vs hue, dark-aware soft tints
- AdminLayout: reuse applyBrand() (no divergence with store)
- Topbar: swatch shows the exact fixed color
- tests: fixed-color apply, dark soft, and override-cleanup on switch

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

assets/admin/stores/uiStore.test.ts

@@ -55,6 +55,37 @@ describe('brandHue', () => {
         expect(document.documentElement.style.getPropertyValue('--brand-h')).toBe(String(hue.h));
         expect(document.documentElement.style.getPropertyValue('--brand-c')).toBe(String(hue.c));
     });
+
+    it('گزینه نارنجی با رنگ ثابت rgb(241,119,50) وجود دارد', () => {
+        const orange = HUES.find((h) => h.name === 'نارنجی');
+        expect(orange?.fixed?.primary).toBe('rgb(241, 119, 50)');
+    });
+
+    it('انتخاب نارنجی، --primary را دقیقاً rgb(241,119,50) و soft روشن را inline می‌کند', () => {
+        const orange = HUES.find((h) => h.fixed)!;
+        useUiStore.getState().setBrandHue(orange);
+        const s = document.documentElement.style;
+        expect(s.getPropertyValue('--primary')).toBe('rgb(241, 119, 50)');
+        expect(s.getPropertyValue('--primary-soft')).toBe(orange.fixed!.soft);
+        expect(s.getPropertyValue('--ring')).toBe(orange.fixed!.ring);
+    });
+
+    it('در حالت تیره، soft تیره اعمال می‌شود', () => {
+        const orange = HUES.find((h) => h.fixed)!;
+        useUiStore.getState().toggleDarkMode(); // dark
+        useUiStore.getState().setBrandHue(orange);
+        expect(document.documentElement.style.getPropertyValue('--primary-soft'))
+            .toBe(orange.fixed!.softDark);
+    });
+
+    it('برگشت به hue بدون رنگ ثابت، override اینلاین --primary را پاک می‌کند', () => {
+        const orange = HUES.find((h) => h.fixed)!;
+        useUiStore.getState().setBrandHue(orange);
+        expect(document.documentElement.style.getPropertyValue('--primary')).not.toBe('');
+        useUiStore.getState().setBrandHue(HUES[0]); // بنفش، بدون fixed
+        expect(document.documentElement.style.getPropertyValue('--primary')).toBe('');
+        expect(document.documentElement.style.getPropertyValue('--primary-soft')).toBe('');
+    });
 });
 
 describe('settingsPanel', () => {