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/EscalateModal.tsx

@@ -35,9 +35,9 @@ export function EscalateModal({ open, onClose, onEscalate, isProcessing, hasPsaT
   return (
     <Modal isOpen={open} onClose={handleClose} title="Escalate Session" size="sm">
       <div className="space-y-4">
-        <div className="flex items-start gap-3 rounded-xl border border-amber-400/20 bg-amber-400/5 p-3">
-          <AlertTriangle size={16} className="text-amber-400 shrink-0 mt-0.5" />
-          <p className="text-sm text-amber-400">
+        <div className="flex items-start gap-3 rounded-xl border border-warning/20 bg-warning/5 p-3">
+          <AlertTriangle size={16} className="text-warning shrink-0 mt-0.5" />
+          <p className="text-sm text-warning">
             This will mark the session as requesting escalation. Team members will see it in their escalation queue and can pick it up with full context.
           </p>
         </div>
@@ -70,7 +70,7 @@ export function EscalateModal({ open, onClose, onEscalate, isProcessing, hasPsaT
           <button
             onClick={handleSubmit}
             disabled={!reason.trim() || reason.trim().length < 5 || isProcessing}
-            className="flex-1 flex items-center justify-center gap-2 rounded-lg bg-amber-500/90 px-4 py-2.5 min-h-[44px] text-sm font-semibold text-white hover:bg-amber-500 active:scale-[0.98] disabled:opacity-40 transition-all"
+            className="flex-1 flex items-center justify-center gap-2 rounded-lg bg-warning px-4 py-2.5 min-h-[44px] text-sm font-semibold text-white hover:bg-warning active:scale-[0.98] disabled:opacity-40 transition-all"
           >
             {isProcessing ? (
               <Loader2 size={14} className="animate-spin" />