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/dashboard/PendingEscalations.tsx

@@ -33,7 +33,7 @@ export function PendingEscalations() {
     >
       <div
         className="flex items-center justify-between px-5 py-3"
-        style={{ borderBottom: '1px solid var(--glass-border)' }}
+        style={{ borderBottom: '1px solid var(--color-border-default)' }}
       >
         <div className="flex items-center gap-2">
           <AlertTriangle size={14} className="text-amber-400" />
@@ -58,7 +58,7 @@ export function PendingEscalations() {
             className="flex items-center gap-3 px-5 py-3"
             style={{
               borderBottom: i < Math.min(escalations.length, 3) - 1
-                ? '1px solid var(--glass-border)'
+                ? '1px solid var(--color-border-default)'
                 : undefined,
             }}
           >