refactor: normalize FlowPilot/Assistant/ScriptBuilder to design system tokens

Replace hardcoded Tailwind color utilities with semantic CSS variable tokens
across 31 files in the FlowPilot, Assistant Chat, and Script Builder feature
communities — the areas graphify identified as design-system-free.

- text-blue-400 → text-accent, bg-blue-500/10 → bg-accent-dim, border-blue-500/20 → border-accent/20
- text-amber-400 → text-warning, bg-amber-400/10 → bg-warning-dim, border-l-amber-500 → border-l-warning
- text-rose-400/500 → text-danger, bg-rose-500/10 → bg-danger-dim
- text-emerald-400 → text-success, bg-emerald-500/10 → bg-success-dim, border-l-emerald-500 → border-l-success
- bg-white/[0.08] → bg-elevated (opacity hack → semantic surface token)
- bg-gradient-to-r from-blue-500 to-blue-400 → bg-accent (no gradient surfaces)
- bg-[#60a5fa] → bg-accent (hard-coded hex removed)

Also adds graphify-out/ to .gitignore.

Theme resilience: accent color has changed twice in 5 weeks. Semantic tokens
mean the next change is a 1-line edit in index.css, not 110 grep-and-replace.

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

frontend/src/components/flowpilot/AISessionListItem.tsx

@@ -9,9 +9,9 @@ interface AISessionListItemProps {
 
 const STATUS_CONFIG = {
   active: { icon: Clock, color: 'text-primary', label: 'Active' },
-  paused: { icon: Pause, color: 'text-amber-400', label: 'Paused' },
-  resolved: { icon: CheckCircle2, color: 'text-emerald-400', label: 'Resolved' },
-  escalated: { icon: ArrowUpRight, color: 'text-amber-400', label: 'Escalated' },
+  paused: { icon: Pause, color: 'text-warning', label: 'Paused' },
+  resolved: { icon: CheckCircle2, color: 'text-success', label: 'Resolved' },
+  escalated: { icon: ArrowUpRight, color: 'text-warning', label: 'Escalated' },
   abandoned: { icon: AlertCircle, color: 'text-text-muted', label: 'Abandoned' },
 } as const
 
@@ -64,7 +64,7 @@ export function AISessionListItem({ session }: AISessionListItemProps) {
           </div>
         </div>
         {session.session_rating && (
-          <span className="font-sans text-xs text-xs text-amber-400">
+          <span className="font-sans text-xs text-xs text-warning">
             {'★'.repeat(session.session_rating)}
           </span>
         )}