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/assistant/ConcludeSessionModal.tsx

@@ -152,7 +152,7 @@ export function ConcludeSessionModal({
         {/* Header */}
         <div
           className="flex items-center justify-between px-6 py-4 border-b shrink-0"
-          style={{ borderColor: 'var(--glass-border)' }}
+          style={{ borderColor: 'var(--color-border-default)' }}
         >
           <div className="flex items-center gap-3">
             <div className="w-9 h-9 rounded-xl bg-accent-dim flex items-center justify-center">
@@ -178,7 +178,7 @@ export function ConcludeSessionModal({
         {/* Step indicator */}
         <div
           className="px-6 py-3 border-b shrink-0 flex items-center gap-2"
-          style={{ borderColor: 'var(--glass-border)' }}
+          style={{ borderColor: 'var(--color-border-default)' }}
         >
           {(['select-outcome', 'add-notes', 'summary'] as ModalStep[]).map((s, i) => (
             <div key={s} className="flex items-center gap-2">
@@ -283,7 +283,7 @@ export function ConcludeSessionModal({
                   }
                   rows={4}
                   className="w-full resize-none rounded-xl border bg-card text-foreground text-sm placeholder:text-muted-foreground px-4 py-3 focus:outline-hidden focus:border-primary/30"
-                  style={{ borderColor: 'var(--glass-border)' }}
+                  style={{ borderColor: 'var(--color-border-default)' }}
                 />
               </div>
 
@@ -309,7 +309,7 @@ export function ConcludeSessionModal({
               {/* Generated summary */}
               <div
                 className="rounded-xl border p-5 bg-card"
-                style={{ borderColor: 'var(--glass-border)' }}
+                style={{ borderColor: 'var(--color-border-default)' }}
               >
                 <div className="flex items-center justify-between mb-3">
                   <span className="font-sans text-xs text-[0.625rem] uppercase tracking-widest text-muted-foreground flex items-center gap-1.5">
@@ -328,7 +328,7 @@ export function ConcludeSessionModal({
         {/* Footer actions */}
         <div
           className="px-6 py-4 border-t shrink-0 flex items-center justify-between gap-3"
-          style={{ borderColor: 'var(--glass-border)' }}
+          style={{ borderColor: 'var(--color-border-default)' }}
         >
           {step === 'select-outcome' && (
             <>