fix(hotkey): surface Esc-to-cancel hint and replace recording-keyframe reuse with success flash

Two scoped fixes to HotkeyRecorder:

- Append "Esc to cancel." to the recording prompt so the existing Escape
  handler is discoverable. srStatus already mentions Escape; no harmonisation
  needed.
- Replace animate-pulse-warm on the captured state with a static
  bg-success/10 + border-success/40 flash. pulse-warm is the
  recording-active keyframe; reusing it for the saved state muddled the
  visual vocabulary. The global * transition rule already animates
  background-color and border-color over --duration-ui (150ms) with the
  brand cubic-bezier ease, so no new keyframe is needed and prefers-reduced-motion
  is honoured automatically. Also swapped transition-all for transition-colors
  to comply with the no-transition-all brand-motion rule.

src/lib/components/HotkeyRecorder.svelte

@@ -189,16 +189,16 @@
       {recording
         ? 'bg-bg-input border-accent shadow-[0_0_0_3px_rgba(201,133,85,0.1)]'
         : captured
-          ? 'bg-bg-input border-border animate-pulse-warm'
+          ? 'bg-success/10 border-success/40'
           : 'bg-bg-input border-border hover:border-border'}
-      border transition-all"
+      border transition-colors"
     onclick={startRecording}
     aria-label={ariaLabel}
     aria-pressed={recording}
   >
     <span class="sr-only" aria-live="polite">{srStatus}</span>
     {#if recording}
-      <span class="text-[11px] text-text-tertiary italic">Hold Ctrl/Alt/Super + key...</span>
+      <span class="text-[11px] text-text-tertiary italic">Hold Ctrl/Alt/Super + key. Esc to cancel.</span>
     {:else}
       {#each chips as chip, i}
         {#if i > 0}