fix(ui): settings modal sizing regression + 17 more folds audit findings

Fix settings modal regression: Modal500 was wrapped in useModalStyle(560),
forcing maxWidth 560px and squishing the two-pane Settings layout (folds
size="500" is ~50rem). Restore desktop width to the folds recipe while
keeping mobile fullscreen.

N-series fixes:
- N13 ScheduledMessagesTray header: <Box as="button"> -> folds <Button>
- N28 composer char counter: drop undefined --tc-surface-low + opacity,
  use priority="300" and config.space token
- N31 collapsible "Read more" toggle: padded <Button> -> flush inline-button
  pattern matching (edited) link
- N41 UserPrivateNotes "Saving..." now shows a folds <Spinner>
- N43 Night Light slider: add accentColor; label opacity -> priority
- N44 mention-highlight Reset: bare <button> -> folds <Button> (drops
  undefined --border-interactive-normal); Boot button kept (TDS-only)
- N45 SelectTheme trigger variant -> Secondary to match SettingsSelect
- N49 RoomInsights StatTile emoji -> folds <Icon> (Photo/VideoCamera/
  Headphone/File)
- N54/N57 PiP overlay badges + fullscreen button: token discipline
  (config.radii/space, folds Text); dark scrim kept for video legibility
- N60 knock badge: match Pinned Messages pattern (no wrapper div, toRem
  insets, no hardcoded size overrides)
- N62 unverified-device banner: 3px left-accent -> standard border via
  color.Warning.ContainerLine; drop opacity hacks
- N65 Edit History: real "Load more" pagination (accumulate next_batch,
  de-dupe by id, re-sort by ts) replacing passive text
- N66 search date fields: raw <input type="date"> -> folds <Input>
- N67 SeasonalEffect z-index 9999 -> 9997 (below Night Light + modals)
- N73 Pending Requests header uses css.MembersGroupLabel
- N74 remove raw em-sized emoji <span> in RoomNavItem name
- N85/N86 RemindMeDialog: <Box role="dialog"> -> folds <Dialog>; preset
  MenuItems -> Buttons (fixes invalid menuitem-in-dialog ARIA)

Document deliberate WON'T FIX rationale for N9, N51, N61, N71, N75, N77.

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

src/app/features/room/RoomInput.tsx

@@ -866,15 +866,15 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
               padding: `${config.space.S100} ${config.space.S200}`,
               borderRadius: config.radii.R300,
               background: color.Warning.Container,
-              borderLeft: `3px solid ${color.Warning.Main}`,
+              border: `${config.borderWidth.B300} solid ${color.Warning.ContainerLine}`,
             }}
           >
             <Icon
               size="100"
               src={Icons.Shield}
-              style={{ color: color.Warning.OnContainer, opacity: 0.8, flexShrink: 0 }}
+              style={{ color: color.Warning.OnContainer, flexShrink: 0 }}
             />
-            <Text size="T200" style={{ color: color.Warning.OnContainer, opacity: 0.9 }}>
+            <Text size="T200" style={{ color: color.Warning.OnContainer }}>
               {roomUnverifiedDeviceCount}{' '}
               {roomUnverifiedDeviceCount === 1 ? 'unverified device' : 'unverified devices'} in this
               room
@@ -1159,14 +1159,13 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
               {charCount > 0 && (
                 <Text
                   size="T200"
+                  priority="300"
                   style={{
-                    color: 'var(--tc-surface-low)',
-                    padding: '0 4px',
+                    padding: `0 ${config.space.S100}`,
                     alignSelf: 'center',
                     userSelect: 'none',
                     minWidth: '2rem',
                     textAlign: 'right',
-                    opacity: 0.7,
                   }}
                 >
                   {charCount}