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/EditorAIPanel.tsx

@@ -50,14 +50,14 @@ export function EditorAIPanel({
         background: 'rgba(16, 17, 20, 0.95)',
         backdropFilter: 'var(--glass-blur)',
         WebkitBackdropFilter: 'var(--glass-blur)',
-        borderColor: 'var(--glass-border)',
+        borderColor: 'var(--color-border-default)',
         animation: 'slideInRight 200ms ease-out',
       }}
     >
       {/* Header */}
       <div
         className="flex items-center justify-between px-4 py-3 border-b shrink-0"
-        style={{ borderColor: 'var(--glass-border)' }}
+        style={{ borderColor: 'var(--color-border-default)' }}
       >
         <div className="flex items-center gap-2">
           <Sparkles size={16} className="text-primary" />
@@ -74,7 +74,7 @@ export function EditorAIPanel({
       <NodeSummary node={focalNode} flowName={flowName} flowType={flowType} nodeCount={nodeCount} />
 
       {/* Tabs */}
-      <div className="flex border-b shrink-0" style={{ borderColor: 'var(--glass-border)' }}>
+      <div className="flex border-b shrink-0" style={{ borderColor: 'var(--color-border-default)' }}>
         <button
           onClick={() => setActiveTab('chat')}
           className={cn(