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/account/ChatRetentionSettingsPage.tsx

@@ -74,7 +74,7 @@ export default function ChatRetentionSettingsPage() {
               min={1}
               max={365}
               className="w-full rounded-xl border bg-card text-foreground text-sm px-4 py-2.5 focus:outline-hidden focus:border-primary/30"
-              style={{ borderColor: 'var(--glass-border)' }}
+              style={{ borderColor: 'var(--color-border-default)' }}
             />
             <p className="text-xs text-muted-foreground mt-1">
               Chats older than this will be automatically deleted (1-365 days)
@@ -92,7 +92,7 @@ export default function ChatRetentionSettingsPage() {
               min={10}
               max={10000}
               className="w-full rounded-xl border bg-card text-foreground text-sm px-4 py-2.5 focus:outline-hidden focus:border-primary/30"
-              style={{ borderColor: 'var(--glass-border)' }}
+              style={{ borderColor: 'var(--color-border-default)' }}
             />
             <p className="text-xs text-muted-foreground mt-1">
               When this limit is exceeded, oldest unpinned chats are deleted

frontend/src/pages/account/IntegrationsPage.tsx

@@ -813,7 +813,7 @@ function MemberMappingTab({ connection }: { connection: PsaConnectionResponse |
                       onChange={(e) => handleMemberChange(user.user_id, e.target.value)}
                       className={cn(
                         'w-full rounded-lg border bg-card px-3 py-1.5 text-sm text-foreground',
-                        'border-border focus:border-[rgba(6,182,212,0.3)] focus:outline-none',
+                        'border-border focus:border-[rgba(249,115,22,0.3)] focus:outline-none',
                         !currentMapping && 'text-muted-foreground'
                       )}
                     >
@@ -1084,7 +1084,7 @@ function SettingSelect({
         value={value}
         onChange={(e) => onChange(e.target.value)}
         disabled={disabled}
-        className="w-full max-w-xs rounded-lg border border-border bg-card px-3 py-2 text-sm text-foreground focus:border-[rgba(6,182,212,0.3)] focus:outline-none disabled:opacity-50"
+        className="w-full max-w-xs rounded-lg border border-border bg-card px-3 py-2 text-sm text-foreground focus:border-[rgba(249,115,22,0.3)] focus:outline-none disabled:opacity-50"
       >
         {options.map((opt) => (
           <option key={opt.value} value={opt.value}>{opt.label}</option>