fix(home): stop the monitor banner crash, and polish Home/map/settings UI

lib/app/shell/main_shell.dart

@@ -13,7 +13,6 @@ import 'package:dpip/shared/map/map_camera_handoff.dart';
 import 'package:dpip/shared/map/map_trace.dart';
 import 'package:dpip/shared/navigation/app_routes.dart';
 import 'package:dpip/shared/navigation/refresh_on_appear.dart';
-import 'package:dpip/shared/widgets/permission_banners.dart';
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:provider/provider.dart';
@@ -204,11 +203,8 @@ class _MainShellState extends State<MainShell> with RouteAware {
     return Scaffold(
       // Let the Home weather backdrop show through behind the bar.
       extendBody: true,
-      // A location "fix it" banner sits above the active tab (zero height when
-      // location is healthy, so Home's full-bleed layout is unaffected).
       body: Column(
         children: [
-          const PermissionBanners(),
           // Renders nothing; checks once after the first frame whether this
           // build's channel has a newer release, and says so once per version.
           const UpdatePrompt(),

lib/app/theme/app_glass.dart

@@ -46,43 +46,60 @@ const double glassRevealedAlpha = 0.20;
 
 /// The translucent card/surface tint: resting
 /// [ColorScheme.surfaceContainerHighest] → the reference's sky-tinted 20 % fill as
-/// [reveal] rises.
+/// [reveal] rises — **dark theme only**. Light theme skips the fade entirely
+/// and stays [ColorScheme.surfaceContainerLow] at every [reveal] — the same
+/// solid fill [Card] itself defaults to (see the Material 3 `_CardDefaultsM3`
+/// this mirrors), so a light-theme card here reads exactly as crisp as the
+/// plain [Card] the EEW alert uses, not merely "less translucent." Any partial
+/// alpha over a busy backdrop, even 90-odd percent, still reads as hazy next
+/// to that fully opaque comparison.
 ///
 /// Without a [sky] colour (no backdrop running, or before the first LUT bake)
-/// it falls back to a near-opaque theme surface, because 20 % of nothing is an
-/// unreadable card.
-Color glassSurface(
-  ColorScheme colors,
-  double reveal, {
-  Color? sky,
-  int? hour,
-}) => Color.lerp(
-  colors.surfaceContainerHighest.withValues(alpha: 0.55),
-  sky == null
+/// dark theme falls back to a near-opaque theme surface, because 20 % of
+/// nothing is an unreadable card.
+Color glassSurface(ColorScheme colors, double reveal, {Color? sky, int? hour}) {
+  if (colors.brightness == Brightness.light) return colors.surfaceContainerLow;
+  final revealed = sky == null
       ? colors.surface.withValues(alpha: 0.92)
-      : skyCardTint(sky, hour: hour ?? AppTime.utc8.hour),
-  reveal,
-)!;
+      : skyCardTint(sky, hour: hour ?? AppTime.utc8.hour);
+  return Color.lerp(
+    colors.surfaceContainerHighest.withValues(alpha: 0.55),
+    revealed,
+    reveal,
+  )!;
+}
 
 /// Ink for content **inside** a [glassSurface] card.
 ///
-/// At rest the card is its own plate and the theme's on-surface roles are
-/// right. Once [reveal] dissolves it to the 20 % fill above, the card is no
-/// longer a plate — it is a pane of the sky — so its ink has to follow the sky
-/// exactly the way [inkOverWeather] does. Leaving it on [ColorScheme.onSurface]
-/// puts near-black text on a rain sky in a light theme.
+/// Dark theme: at rest the card is its own plate and the theme's on-surface
+/// roles are right. Once [reveal] dissolves it to the 20 % fill above, the
+/// card is no longer a plate — it is a pane of the sky — so its ink has to
+/// follow the sky exactly the way [inkOverWeather] does. Leaving it on
+/// [ColorScheme.onSurface] puts near-black text on a rain sky.
+///
+/// Light theme: [glassSurface] stays an opaque plate at every [reveal], so
+/// this stays [ColorScheme.onSurface] unconditionally — shifting it toward
+/// white for a dark [skyIsLight] would put pale text on that still-opaque,
+/// still-light plate.
 Color glassOnSurface(
   ColorScheme colors, {
   double reveal = 0,
   bool skyIsLight = false,
-}) => inkOverWeather(colors, reveal, skyIsLight: skyIsLight);
+}) {
+  if (colors.brightness == Brightness.light) return colors.onSurface;
+  return inkOverWeather(colors, reveal, skyIsLight: skyIsLight);
+}
 
-/// Secondary ink for content inside a [glassSurface] card.
+/// Secondary ink for content inside a [glassSurface] card. See [glassOnSurface]
+/// for why light theme skips the sky-following shift.
 Color glassOnSurfaceVariant(
   ColorScheme colors, {
   double reveal = 0,
   bool skyIsLight = false,
-}) => inkOverWeatherVariant(colors, reveal, skyIsLight: skyIsLight);
+}) {
+  if (colors.brightness == Brightness.light) return colors.onSurfaceVariant;
+  return inkOverWeatherVariant(colors, reveal, skyIsLight: skyIsLight);
+}
 
 /// Whether [mode]'s sky is light enough that dark foregrounds read better than
 /// white once the weather backdrop is showing.

lib/core/settings/locale_config.dart

@@ -5,6 +5,7 @@ import 'package:dpip/l10n/gen/app_localizations.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
+import 'package:intl/intl.dart';
 
 /// The app's home locale: Traditional Chinese for Taiwan (`zh_TW`).
 ///
@@ -98,6 +99,21 @@ bool _isBareChinese(Locale locale) =>
     locale.scriptCode == null &&
     locale.countryCode == null;
 
+/// A `DateFormat`-safe locale tag for [locale].
+///
+/// `intl` ships its own locale-data set, entirely separate from
+/// `flutter_localizations` — it does not know every locale this app
+/// supports either (`yue` included, the same gap the widgets-fallback
+/// delegates above patch for Material/Cupertino). Asking `DateFormat` to
+/// format with a tag it has no data for throws ("Invalid locale") rather than
+/// falling back, so every `DateFormat` call driven by the app's locale must
+/// go through this first. Falls back to [kHomeLocale], the same replacement
+/// the Material/Cupertino delegates use.
+String intlDateLocale(Locale locale) {
+  final tag = locale.toString();
+  return DateFormat.localeExists(tag) ? tag : kHomeLocale.toString();
+}
+
 /// Picks the best supported locale for [deviceLocales].
 ///
 /// Chinese needs an explicit script/region split: bare `zh` and `zh_Hant` map

lib/features/changelog/presentation/pages/changelog_page.dart

@@ -5,6 +5,7 @@ import 'package:dpip/app/theme/app_motion.dart';
 import 'package:dpip/app/theme/app_radius.dart';
 import 'package:dpip/app/theme/app_spacing.dart';
 import 'package:dpip/core/logging/log.dart';
+import 'package:dpip/core/settings/locale_config.dart';
 import 'package:dpip/core/version/app_build.dart';
 import 'package:dpip/core/error/result.dart';
 import 'package:dpip/features/changelog/domain/changelog_repository.dart';
@@ -276,8 +277,9 @@ class _ReleaseTile extends StatelessWidget {
         ? Icons.science_outlined
         : Icons.verified_outlined;
     final title = note.name.isEmpty ? note.tagName : note.name;
-    final date = DateFormat.yMMMd(Localizations.localeOf(context).toString())
-        .format(note.publishedAt.toLocal());
+    final date = DateFormat.yMMMd(
+      intlDateLocale(Localizations.localeOf(context)),
+    ).format(note.publishedAt.toLocal());
     final emphasized = isCurrent || expanded;
 
     return CustomPaint(

lib/features/changelog/presentation/pages/version_notes_page.dart

@@ -12,6 +12,7 @@ library;
 import 'package:dpip/app/theme/app_radius.dart';
 import 'package:dpip/app/theme/app_spacing.dart';
 import 'package:dpip/core/logging/log.dart';
+import 'package:dpip/core/settings/locale_config.dart';
 import 'package:dpip/core/version/app_build.dart';
 import 'package:dpip/features/changelog/domain/changelog_repository.dart';
 import 'package:dpip/features/changelog/domain/release_note.dart';
@@ -137,8 +138,9 @@ class _Header extends StatelessWidget {
     final colors = theme.colorScheme;
     final typeColor = isStable ? _stableColor : _snapshotColor;
     final title = note.name.isEmpty ? note.tagName : note.name;
-    final date = DateFormat.yMMMd(Localizations.localeOf(context).toString())
-        .format(note.publishedAt.toLocal());
+    final date = DateFormat.yMMMd(
+      intlDateLocale(Localizations.localeOf(context)),
+    ).format(note.publishedAt.toLocal());
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [

lib/features/earthquake/presentation/pages/report_list_page.dart

@@ -4,6 +4,7 @@ library;
 import 'package:dpip/app/theme/app_radius.dart';
 import 'package:dpip/app/theme/app_spacing.dart';
 import 'package:dpip/core/realtime/app_time.dart';
+import 'package:dpip/core/settings/locale_config.dart';
 import 'package:dpip/shared/seismic/intensity.dart';
 import 'package:dpip/features/earthquake/domain/partial_earthquake_report.dart';
 import 'package:dpip/features/earthquake/domain/report_repository.dart';
@@ -238,7 +239,7 @@ class _DaySection extends StatelessWidget {
     final theme = Theme.of(context);
     final colors = theme.colorScheme;
     final l10n = AppLocalizations.of(context);
-    final locale = Localizations.localeOf(context).toString();
+    final locale = intlDateLocale(Localizations.localeOf(context));
 
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,

lib/features/home/presentation/pages/home_page.dart

@@ -302,31 +302,75 @@ class _HomePageState extends State<HomePage> {
                           blend: HomeChrome.regionBlend(sheetExtent.value),
                           dismiss: HomeChrome.regionDismiss(sheetExtent.value),
                         ),
-                        builder: (context, dials, _) => Column(
-                          mainAxisSize: MainAxisSize.min,
-                          children: [
-                            RegionBar(
-                              blend: dials.blend,
-                              dismiss: dials.dismiss,
-                              skyIsLight: skyIsLightFrom(sky, weatherMode),
-                            ),
-                            // Quick link to 強震監視器 — same dials as the
-                            // region bar above it, so the two move as one
-                            // piece of chrome as the sheet rises.
-                            //
-                            // Above the support pill on purpose: this one
-                            // only renders while an alert is active, and an
-                            // alert must not be pushed down the screen by a
-                            // donation prompt. When nothing is happening it
-                            // draws nothing, so the pill sits directly under
-                            // the bar anyway.
-                            HomeMonitorBanner(dismiss: dials.dismiss),
-                            _GoldSupportBar(
-                              blend: dials.blend,
-                              dismiss: dials.dismiss,
-                            ),
-                          ],
-                        ),
+                        builder: (context, dials, _) {
+                          // Quick link to 強震監視器. The gold support bar's
+                          // top edge always sits flush under the region bar
+                          // — its position never moves. When an alert is
+                          // live, its card is anchored to that same top
+                          // edge and, being the taller of the two, sits
+                          // directly over it: real Z-axis overlap, with the
+                          // card's own elevation shadow falling across the
+                          // bar underneath, not just first-in-a-list order.
+                          // `isActive` is the same check
+                          // HomeMonitorBanner.build gates its own render on,
+                          // shared so this layout math can't drift from it.
+                          final hasActiveEew = HomeMonitorBanner.isActive(
+                            context,
+                          );
+                          final stackHeight = hasActiveEew
+                              ? HomeMonitorBanner.height
+                              : _GoldSupportBar.height;
+                          return Column(
+                            mainAxisSize: MainAxisSize.min,
+                            children: [
+                              RegionBar(
+                                blend: dials.blend,
+                                dismiss: dials.dismiss,
+                                skyIsLight: skyIsLightFrom(sky, weatherMode),
+                              ),
+                              SizedBox(
+                                height: stackHeight,
+                                child: Stack(
+                                  clipBehavior: Clip.none,
+                                  children: [
+                                    Positioned(
+                                      top: 0,
+                                      left: 0,
+                                      right: 0,
+                                      child: _GoldSupportBar(
+                                        blend: dials.blend,
+                                        dismiss: dials.dismiss,
+                                      ),
+                                    ),
+                                    // Always mounted — HomeMonitorBanner
+                                    // renders SizedBox.shrink() internally
+                                    // while calm. Wrapping this in `if
+                                    // (hasActiveEew)` instead (removing the
+                                    // Positioned from the Stack's children
+                                    // entirely on every toggle) is what
+                                    // triggered a real Flutter engine crash
+                                    // here: a semantics assertion
+                                    // (`!child.attached`) when the Material
+                                    // + InkWell subtree underneath is
+                                    // repeatedly unmounted and remounted at
+                                    // this position. Letting the banner's
+                                    // own build() switch its child instead
+                                    // keeps the element permanently in the
+                                    // tree, which does not hit that bug.
+                                    Positioned(
+                                      top: 0,
+                                      left: 0,
+                                      right: 0,
+                                      child: HomeMonitorBanner(
+                                        dismiss: dials.dismiss,
+                                      ),
+                                    ),
+                                  ],
+                                ),
+                              ),
+                            ],
+                          );
+                        },
                       ),
                 ),
               ),
@@ -351,6 +395,10 @@ class _GoldSupportBar extends StatelessWidget {
   final double blend;
   final double dismiss;
 
+  /// This bar's own rendered height — used to size the overlap stack that
+  /// lets [HomeMonitorBanner] float over its top edge.
+  static const double height = 30;
+
   @override
   Widget build(BuildContext context) {
     final l10n = AppLocalizations.of(context);
@@ -369,7 +417,7 @@ class _GoldSupportBar extends StatelessWidget {
             child: InkWell(
               onTap: () => context.pushNamed(AppRoutes.sponsor),
               child: SizedBox(
-                height: 30,
+                height: height,
                 child: Row(
                   mainAxisAlignment: MainAxisAlignment.center,
                   mainAxisSize: MainAxisSize.max,