fix(ui): replace ungated invented CSS vars with folds tokens (native-cinny audit 1/N)

Audit of our delta vs Cinny v4.12.3 found invented CSS vars (--tc-*, --bg-*)
used outside Lotus-Terminal-gated code, which render unstyled/wrong on stock
themes. Batch 1:
- MemberVerificationBadge: --tc-positive/warning-normal -> color.Success/Warning.Main
- RoomInput (gif/location errors): --tc-danger-normal -> color.Critical.Main
- MsgTypeRenderers (location iframe): --bg-surface-border -> color.SurfaceVariant.ContainerLine
- MessageSearch (cached-room row): --bg-surface-variant -> color.SurfaceVariant.Container
- PrescreenControls (mic-denied): --tc-critical-high -> color.Critical.Main

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/features/room/RoomInput.tsx

@@ -1106,7 +1106,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
                 <Text
                   size="T200"
                   style={{
-                    color: 'var(--tc-danger-normal)',
+                    color: color.Critical.Main,
                     padding: '2px 6px',
                     alignSelf: 'center',
                     whiteSpace: 'nowrap',
@@ -1119,7 +1119,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
                 <Text
                   size="T200"
                   style={{
-                    color: 'var(--tc-danger-normal)',
+                    color: color.Critical.Main,
                     padding: '2px 6px',
                     alignSelf: 'center',
                     whiteSpace: 'nowrap',