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/FlowPilotSession.tsx

@@ -148,7 +148,7 @@ export function FlowPilotSession({
             <div className="mb-4">
               <button
                 onClick={() => setShowShareCommunication(true)}
-                className="flex items-center gap-2 rounded-lg bg-blue-500/10 border border-blue-500/20 px-4 py-2.5 text-sm font-medium text-blue-400 hover:bg-blue-500/20 transition-colors"
+                className="flex items-center gap-2 rounded-lg bg-accent-dim border border-accent/20 px-4 py-2.5 text-sm font-medium text-accent hover:bg-accent/20 transition-colors"
               >
                 <FileText size={16} />
                 {shareLabel}