fix: eliminate deprecated cyan, glass-border, and off-palette colors site-wide

- Replace all rgba(6,182,212,...) cyan focus borders and accents with
  rgba(249,115,22,...) ember orange across 21+ component files
- Remove all var(--glass-border) references (undefined variable) with
  var(--color-border-default) across 24 files
- Remove deprecated blur orbs and glass-morphism effects from
  SurveyPage, SurveyThankYouPage, and LoginPage
- Migrate landing.css from hardcoded hex to CSS custom properties
  (~97 replacements for single-source theming)
- Fix off-palette grays in FlowPilotAnalyticsPage chart styling
  (#8891a0 → #848b9b, #18191f → var(--color-bg-card))
- Update stale comments: "cyan brand" → "accent brand" in GlowEdge,
  "gradient cyan square" → "gradient orange square" in BrandLogo
- Rename glow-cyan SVG filter ID to glow-accent
- Fix category color comment: "cyan" → "deep orange"

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/editor-ai/NodeSummary.tsx

@@ -22,7 +22,7 @@ const NODE_COLORS: Record<string, string> = {
 export function NodeSummary({ node, flowName, flowType, nodeCount }: NodeSummaryProps) {
   if (!node) {
     return (
-      <div className="border-b px-3 py-2.5" style={{ borderColor: 'var(--glass-border)' }}>
+      <div className="border-b px-3 py-2.5" style={{ borderColor: 'var(--color-border-default)' }}>
         <div className="flex items-center gap-2">
           <Layout className="h-3.5 w-3.5 text-muted-foreground" />
           <span className="text-xs font-medium text-foreground truncate">
@@ -41,7 +41,7 @@ export function NodeSummary({ node, flowName, flowType, nodeCount }: NodeSummary
   const colorClass = NODE_COLORS[node.type] || 'text-muted-foreground'
 
   return (
-    <div className="border-b px-3 py-2.5" style={{ borderColor: 'var(--glass-border)' }}>
+    <div className="border-b px-3 py-2.5" style={{ borderColor: 'var(--color-border-default)' }}>
       <div className="flex items-center gap-2">
         <Icon className={`h-3.5 w-3.5 ${colorClass}`} />
         <span className="font-sans text-[0.625rem] uppercase tracking-widest text-muted-foreground">