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/pages/SurveyThankYouPage.tsx

@@ -6,20 +6,8 @@ export default function SurveyThankYouPage() {
     <>
     <PageMeta title="Thank You" description="Thank you for your feedback on ResolutionFlow" />
     <div className="min-h-screen bg-background text-foreground">
-      {/* Atmosphere orbs */}
-      <div className="pointer-events-none fixed inset-0 z-0 overflow-hidden" aria-hidden="true">
-        <div
-          className="absolute"
-          style={{ top: '-200px', left: '-100px', width: '600px', height: '600px', borderRadius: '50%', background: 'radial-gradient(circle, rgba(6, 182, 212, 0.12) 0%, rgba(6, 182, 212, 0.03) 40%, transparent 70%)', filter: 'blur(80px)' }}
-        />
-        <div
-          className="absolute"
-          style={{ bottom: '-150px', right: '-100px', width: '500px', height: '500px', borderRadius: '50%', background: 'radial-gradient(circle, rgba(52, 211, 153, 0.08) 0%, rgba(52, 211, 153, 0.02) 40%, transparent 70%)', filter: 'blur(80px)' }}
-        />
-      </div>
-
       {/* Top bar */}
-      <div className="sticky top-0 z-50" style={{ WebkitBackdropFilter: 'blur(20px)', background: 'rgba(16, 17, 20, 0.85)', borderBottom: '1px solid var(--glass-border)' }}>
+      <div className="sticky top-0 z-50" style={{ background: 'rgba(26, 28, 35, 0.95)', borderBottom: '1px solid var(--color-border-default)' }}>
         <div className="mx-auto flex max-w-[680px] items-center justify-between gap-3 px-5 py-3.5">
           <a href="https://resolutionflow.com" target="_blank" rel="noreferrer" className="flex items-center gap-2.5 text-sm font-heading font-bold text-muted-foreground no-underline">
             <BrandLogo size="sm" />
@@ -31,7 +19,7 @@ export default function SurveyThankYouPage() {
       <div className="relative z-10 mx-auto max-w-[680px] px-5">
         <div className="text-center pt-[120px] animate-fade-in-up">
           {/* Success icon */}
-          <div className="w-20 h-20 mx-auto mb-6 rounded-full flex items-center justify-center" style={{ background: 'rgba(52, 211, 153, 0.1)', border: '1px solid rgba(52, 211, 153, 0.15)' }}>
+          <div className="w-20 h-20 mx-auto mb-6 rounded-full flex items-center justify-center" style={{ background: 'var(--color-success-dim)', border: '1px solid rgba(52, 211, 153, 0.15)' }}>
             <svg width="36" height="36" viewBox="0 0 24 24" fill="none" stroke="oklch(0.76 0.15 163)" strokeWidth="2">
               <path d="M20 6L9 17l-5-5"/>
             </svg>
@@ -48,7 +36,7 @@ export default function SurveyThankYouPage() {
           </p>
 
           {/* Divider */}
-          <div className="mx-auto w-12 h-px mb-10" style={{ background: 'var(--glass-border)' }} />
+          <div className="mx-auto w-12 h-px mb-10" style={{ background: 'var(--color-border-default)' }} />
 
           {/* Feedback callout */}
           <div