feat(brand): adopt official Ordinis logo assets

Делёные design team 2026-05-11 в Downloads/files:
  - ordinis-mark.svg — двойные орбиты + 6 dots + gradient core
    (DeepBlue #185FA5 → SkyBlue #378ADD), brand spec
  - ordinis-favicon.svg — minimal 32px variant
  - ordinis-appicon.svg — 1024px PWA icon с dark rounded tile
  - ordinis-lockup-light/dark.svg — horizontal lockup с wordmark
    (для landing/splash/marketing — пока не используется но
    хранится в public для future use)

Changes:
- public/favicon.svg → minimal 32px variant
- Sidebar logo block: inline ordinis-mark с двойными орбитами +
  gradient core. Wordmark 'ORDINIS MDM' остаётся в Tektur.
- index.html: theme-color #185FA5 (был #120a8f), apple-touch-icon
  link на appicon, mask-icon color match.

Note: SVG colors hardcoded в Sidebar inline для full design fidelity
(brand assets specifically defined gradient). currentColor не подходит
т.к. brand требует точные DeepBlue/SkyBlue/LightBlue tokens.

ordinis-admin-ui/src/components/layout/Sidebar.tsx

@@ -175,20 +175,35 @@ function SidebarContent({
           onClick={onNavigate}
           title="ORDINIS MDM"
         >
-          {/* Brand orbit icon per redesign/ui-kit.html .brand SVG:
-              outer ring r=13 + inner faded ring r=6 + orbit dot offset right cx=22.5. */}
+          {/* Ordinis mark — official brand asset (public/ordinis-mark.svg).
+              Двойные орбиты + 6 dots + gradient core (DeepBlue → SkyBlue).
+              Asset из Downloads/files делёный design team 2026-05-11. */}
           <svg
-            width="24"
-            height="24"
-            viewBox="0 0 32 32"
+            width="26"
+            height="26"
+            viewBox="0 0 256 256"
             fill="none"
             xmlns="http://www.w3.org/2000/svg"
             aria-hidden
-            className="shrink-0 text-accent"
+            className="shrink-0"
           >
-            <circle cx="16" cy="16" r="13" stroke="currentColor" strokeWidth="1.6" />
-            <circle cx="16" cy="16" r="6" stroke="currentColor" strokeWidth="1" opacity="0.45" />
-            <circle cx="22.5" cy="16" r="2.2" fill="currentColor" />
+            <defs>
+              <linearGradient id="ord-sidebar-core" x1="0" y1="0" x2="1" y2="1">
+                <stop offset="0" stopColor="#378ADD" />
+                <stop offset="1" stopColor="#185FA5" />
+              </linearGradient>
+            </defs>
+            <g transform="translate(128 128)">
+              <circle r="96" fill="none" stroke="#B5D4F4" strokeWidth="1.2" />
+              <circle r="62" fill="none" stroke="#B5D4F4" strokeWidth="1.2" />
+              <circle cx="96" cy="0" r="8" fill="#185FA5" />
+              <circle cx="-48" cy="83.14" r="8" fill="#378ADD" />
+              <circle cx="-48" cy="-83.14" r="8" fill="#378ADD" />
+              <circle cx="-62" cy="0" r="6.4" fill="#185FA5" />
+              <circle cx="31" cy="-53.69" r="6.4" fill="#378ADD" />
+              <circle cx="31" cy="53.69" r="6.4" fill="#378ADD" />
+              <circle r="15" fill="url(#ord-sidebar-core)" />
+            </g>
           </svg>
           {!collapsed && (
             <span className="font-display text-[15px] font-semibold leading-none tracking-[0.22em] text-ink inline-flex items-baseline gap-1.5">