design(premiere-plugin): align panel UI with Dragonflight web-ui design system (v1.2.0)

Rewrites css/styles.css to mirror services/web-ui/src/css/components/*
exactly. Brings the Premiere panel into pixel-level parity with the
main Dragonflight web UI:

- Tokens: add --accent-hover, --accent-bright, --thumb-black, --overlay,
  --shadow, --signal-info, motion tokens (ease-out-quart, ease-out-expo,
  dur-fast/normal/slide), z-layer vars. Keep --status-* aliases pointing
  at --signal-* for main.js backwards-compat. Remove unused --accent-dim
  (hue 52 leftover).

- Buttons: match wd-btn — md=32px (was 28px), sm=28px, lg=36px, icon=28sq.
  focus-visible accent-subtle outline. active opacity 0.85. Replace
  hardcoded oklch(68%) hover with --accent-hover. btn-danger now solid
  signal-bad like wd-btn--danger (was transparent w/ red border).

- Inputs/select/search-input: 32px tall, bg-deep background (was
  bg-surface), accent-subtle focus outline matching wd-input.

- Slide panel: 460px wide (was 420), 52px header (was 40), 18px body
  padding, --overlay scrim, ease-out-expo transform. min-height:0 on body.

- Asset card: removed fixed 155px height (now intrinsic), thumb-black bg
  for thumbnails, brightness 1.04 hover filter mirroring wd-card-asset.

- Status badges: 18px tall like wd-badge, font-sans, 0.08em tracking.

- Chips: 18px tall, font-sans (was font-mono 20px), wd-badge proportions.

- Tabs: 36px, accent underline on active, badge styled as pill.

- Empty state, progress bar, preset cards, clip list, message banners,
  form groups, details panel, action bar, connection bar — all spacing
  + typography refined to web-ui standards.

Manifest bumped to 1.2.0. No JS changes required.: manifest.xml

services/premiere-plugin/CSXS/manifest.xml

@@ -2,7 +2,7 @@
 <ExtensionManifest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   ExtensionBundleId="net.wilddragon.dragonflight.panel"
   ExtensionBundleName="Wild Dragon MAM"
-  ExtensionBundleVersion="1.1.0"
+  ExtensionBundleVersion="1.2.0"
   Version="7.0">
   <ExtensionList>
     <Extension Id="net.wilddragon.dragonflight.panel" Version="1.0" />