Fix interface fidelity: invalid Tailwind classes + restore lost HomeScreen

Side-by-side comparison surfaced that several restyle classes silently
generated NO CSS (confirmed against the compiled .next CSS) — invisible
to tests because unit tests assert class strings, not computed styles,
and visual baselines were captured from the broken build.

Root causes fixed:
- rounded-radius-button (51) / rounded-radius-squircle (3) generated
  nothing → every pill/button/chip was border-radius:0. Tailwind v4 maps
  --radius-button to 'rounded-button', not 'rounded-radius-button'.
  Replaced with rounded-full / rounded-[17px].
- duration-normal/fast/slow (58) generated nothing → transitions had
  easing but 0 duration (snapped). Replaced with the token-arbitrary
  form duration-(--duration-normal). (Also fixed an over-replace that
  double-wrapped var(--duration-normal) inside animate-[…] values.)
- HomeScreen.tsx was the OLD emoji version — the R3 rewrite was never
  committed. Restored: brand Chrome/Slack squircle tiles, coral
  GradientGlyph icons, 56px tiles with press-scale, and the frosted
  glass dock (bg-white/[0.07] backdrop-blur-[40px] saturate-150).

Targeted gaps from the feedback:
- raised surface --color-surface-warm-muted #1f1f1f → #1a1a1a (composer,
  chips, tabs)
- welcome chips: max-w-[422px] gap-3 → centered 2×2 grid
- composer input + rail nav labels → 14px
- DeviceSizeToggle: Full/Tablet/Phone text → lucide monitor/tablet/
  smartphone icons (aria-label keeps the radio names)
- SW cache bumped v1→v2 so redeployed clients purge the stale bundle
- LeftRail drawer: ref-during-render → prev-state pattern (lint)

Compiled CSS now emits .rounded-full, transition-duration:var(--duration-
normal), border-radius:17px, and shadow-dock-capsule. Button/Avatar unit
tests updated to the real class names. 83 unit tests green.

Co-Authored-By: Claude Fable 5 <[email protected]>

frontend/src/app/(workspace)/credits/page.tsx

@@ -82,7 +82,7 @@ export default async function CreditsPage() {
           </div>
           <a
             href="mailto:[email protected]"
-            className="rounded-radius-button border border-border px-4 py-2 text-sm text-foreground transition-colors duration-normal ease-app hover:bg-hover-bg"
+            className="rounded-full border border-border px-4 py-2 text-sm text-foreground transition-colors duration-(--duration-normal) ease-app hover:bg-hover-bg"
           >
             Talk to sales
           </a>