polish: clear 33/34 detector findings (bg-black, animate-bounce, spinner, transition-width, color)

After re-audit/critique cycle the deterministic detector (npx impeccable)
flagged 34 design-spec violations. Knock out 33 of them.

  • 25 × pure-black-white: sed-sweep bg-black/X → bg-dark-950/X across
    18+ files (modal scrims, photo viewer backdrop, code blocks). The
    base resolves to rgba(10,15,26,X) — visually identical to true
    black, satisfies the 'no #000' impeccable rule.
  • 3 × bounce-easing: SuccessNotificationModal celebration icon and
    SyncTab loading arrows used animate-bounce; replaced with
    animate-pulse. Bounce easing reads dated; pulse conveys 'in
    progress' without the cartoon feel.
  • 3 × border-accent-on-rounded: TelegramCallback + VerifyEmail
    spinners used 'border-b-2 border-accent-500' on rounded-full —
    detector reads it as a side-stripe even though it's a ring loader.
    Switch to canonical 'border-2 border-accent-500 border-t-transparent'
    (3/4 ring colored). Same visual, no spec violation.
  • 1 × ai-color-palette: AdminLandingStats had text-purple-400 on a
    gift-stats heading; purple is not in the brand palette. Swap to
    text-accent-400.
  • 1 × layout-transition: TrafficProgressBar.tsx fill bar still used
    transition: width 1.2s (slipped past the earlier optimize pass).
    Convert to transform: scaleX with origin-left. Same gradient, same
    duration, runs on the compositor.

Remaining: 1 finding in third-party Aceternity background-beams-collision
component (indigo-500 gradient on decorative WebGL background) — left
as-is, it's lifted decorative third-party code.

Detector: 34 → 1.

src/components/tickets/MessageMediaGrid.tsx

@@ -116,7 +116,7 @@ export function MessageMediaGrid({
                   loading="lazy"
                 />
                 {isLastVisible && (
-                  <div className="pointer-events-none absolute inset-0 flex items-center justify-center bg-black/60 text-2xl font-semibold text-white">
+                  <div className="pointer-events-none absolute inset-0 flex items-center justify-center bg-dark-950/60 text-2xl font-semibold text-white">
                     +{hiddenCount}
                   </div>
                 )}
@@ -172,7 +172,7 @@ export function MessageMediaGrid({
         photoItems[fullscreenIndex] &&
         createPortal(
           <div
-            className="fixed inset-0 z-[9999] bg-black"
+            className="fixed inset-0 z-[9999] bg-dark-950"
             style={{ touchAction: 'pan-x pan-y pinch-zoom' }}
           >
             <button
@@ -225,7 +225,7 @@ export function MessageMediaGrid({
                     <path strokeLinecap="round" strokeLinejoin="round" d="M9 5l7 7-7 7" />
                   </svg>
                 </button>
-                <div className="absolute bottom-6 left-1/2 z-10 -translate-x-1/2 rounded-full bg-black/70 px-3 py-1 text-sm text-white">
+                <div className="absolute bottom-6 left-1/2 z-10 -translate-x-1/2 rounded-full bg-dark-950/70 px-3 py-1 text-sm text-white">
                   {fullscreenIndex + 1} / {photoItems.length}
                 </div>
               </>