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/session/AddSupportingDataModal.tsx

@@ -166,7 +166,7 @@ export function AddSupportingDataModal({ isOpen, onClose, sessionId, onAdded }:
           className={cn(
             'w-full rounded-md 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-hidden focus:ring-1 focus:ring-primary/20'
+            'focus:border-[rgba(249,115,22,0.3)] focus:outline-hidden focus:ring-1 focus:ring-primary/20'
           )}
         />
       </div>
@@ -186,7 +186,7 @@ export function AddSupportingDataModal({ isOpen, onClose, sessionId, onAdded }:
             className={cn(
               'w-full resize-y rounded-md border border-border bg-card px-3 py-2 text-sm',
               'font-mono text-foreground placeholder:text-muted-foreground',
-              'focus:border-[rgba(6,182,212,0.3)] focus:outline-hidden focus:ring-1 focus:ring-primary/20'
+              'focus:border-[rgba(249,115,22,0.3)] focus:outline-hidden focus:ring-1 focus:ring-primary/20'
             )}
           />
         </div>