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/flowpilot/ProposalDetail.tsx

@@ -60,7 +60,7 @@ export function ProposalDetail({ proposal, onReview }: ProposalDetailProps) {
   return (
     <div className="flex h-full flex-col">
       {/* Header */}
-      <div className="border-b px-6 py-4" style={{ borderColor: 'var(--glass-border)' }}>
+      <div className="border-b px-6 py-4" style={{ borderColor: 'var(--color-border-default)' }}>
         <h2 className="font-heading text-lg font-semibold text-foreground">{proposal.title}</h2>
         {proposal.description && (
           <p className="mt-1 text-sm text-muted-foreground">{proposal.description}</p>
@@ -187,7 +187,7 @@ export function ProposalDetail({ proposal, onReview }: ProposalDetailProps) {
             value={reviewNotes}
             onChange={(e) => setReviewNotes(e.target.value)}
             placeholder="Reviewer notes (optional)"
-            className="w-full rounded-lg border border-border bg-card px-3 py-2 text-sm text-foreground placeholder:text-muted-foreground focus:border-[rgba(6,182,212,0.3)] focus:outline-none"
+            className="w-full rounded-lg border border-border bg-card px-3 py-2 text-sm text-foreground placeholder:text-muted-foreground focus:border-[rgba(249,115,22,0.3)] focus:outline-none"
           />
 
           {/* Action buttons */}