fix(design): code-reviewer polish — dedupe tag-mitre recipe, drop dead boxShadow tokens, cover StatusBadge classes

F1: MitreTechniqueTag inline classes replaced with className="tag-mitre gap-xxs"
    (index.css .tag-mitre is now the single source of truth for technique tags).
F2: boxShadow block removed from tailwind.config.ts — no component referenced
    shadow-soft-lift / shadow-floating / *-dark; DESIGN.md §Don'ts prohibits shadows.
F4: StatusBadge.test.tsx gains 3 class assertions (bg-warn-soft / bg-primary-soft / bg-cloud)
    mirroring SimulationStatusBadge.test.tsx pattern. Test count: 136 → 139.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/tailwind.config.ts

@@ -98,13 +98,6 @@ const config: Config = {
         none: '0px',
         pill: '9999px',
       },
-      boxShadow: {
-        // Kept in config for backwards compat but no component should apply them
-        'soft-lift': '0 2px 8px rgba(26, 26, 26, 0.08)',
-        floating: '0 8px 24px rgba(26, 26, 26, 0.12)',
-        'soft-lift-dark': '0 2px 8px rgba(0, 0, 0, 0.32)',
-        'floating-dark': '0 8px 24px rgba(0, 0, 0, 0.48)',
-      },
       maxWidth: {
         page: '1366px',
       },