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/kb-accelerator/ReviewScreen.tsx

@@ -89,7 +89,7 @@ export function ReviewScreen({ kbImport, onEditNode, onApproveAll, onCommit, onD
 
         {/* Nodes panel */}
         <div className="flex flex-col card-flat overflow-hidden">
-          <div className="flex items-center gap-2 px-4 py-3 border-b" style={{ borderColor: 'var(--glass-border)' }}>
+          <div className="flex items-center gap-2 px-4 py-3 border-b" style={{ borderColor: 'var(--color-border-default)' }}>
             <span className="text-sm font-medium text-foreground">Generated Flow</span>
             <span className="font-sans text-xs text-[0.625rem] uppercase tracking-[0.1em] text-muted-foreground ml-auto">
               {kbImport.target_type === 'troubleshooting' ? 'Troubleshooting' : 'Project'}

frontend/src/components/kb-accelerator/SourcePanel.tsx

@@ -25,7 +25,7 @@ export function SourcePanel({ sourceText, sourceFormat, highlightExcerpt }: Sour
 
   return (
     <div className="card-flat flex flex-col h-full">
-      <div className="flex items-center gap-2 px-4 py-3 border-b" style={{ borderColor: 'var(--glass-border)' }}>
+      <div className="flex items-center gap-2 px-4 py-3 border-b" style={{ borderColor: 'var(--color-border-default)' }}>
         <FileText size={16} className="text-muted-foreground" />
         <span className="text-sm font-medium text-foreground">Source Document</span>
         <span className="font-sans text-xs text-[0.625rem] uppercase tracking-[0.1em] text-muted-foreground ml-auto">