feat: enforce no hardcoded colors across entire CMS

Added scripts/check-admin-colors.mjs — scans all src/ files for:
- text-white, text-black (use theme text vars)
- bg-white, bg-black (use theme background/overlay vars)
- bg/text/border/ring with gray/slate/zinc/stone palette
- bg/text/border/ring with red/green/blue/etc palette

Fixed 21 violations across 11 files:
- Overlays: bg-black/* → bg-foreground/*
- Text: text-white → text-primary-foreground
- Backgrounds: bg-white/10 → bg-background/10
- Green accents: bg-green-* → bg-primary
- Red accents: bg-red-* → bg-destructive

Integrated into:
- lint-staged: runs on every *.ts/*.tsx commit
- vitest: src/lib/no-hardcoded-colors.test.ts replaces old audit test
- Allowlist: shadcn/ui primitives (button, badge, dialog) + 4 graphical files

src/app/client/client-view.tsx

@@ -228,7 +228,7 @@ export function ClientView({
 				// biome-ignore lint/a11y/noStaticElementInteractions: draggable toolbar with explicit mouse/touch handlers
 				<div
 					ref={toolbarRef}
-					className={`fixed z-[9999] backdrop-blur-xl bg-black/30 rounded-xl border border-white/10 shadow-2xl px-1.5 py-1 select-none ${dragging ? "cursor-grabbing" : "cursor-grab"}`}
+					className={`fixed z-[9999] backdrop-blur-xl bg-foreground/30 rounded-xl border border-white/10 shadow-2xl px-1.5 py-1 select-none ${dragging ? "cursor-grabbing" : "cursor-grab"}`}
 					style={{
 						top: pos.top,
 						left: pos.left,