app: warm-tint the shared palette, fix Snack chip + on-fill contrast

- theme.dart: warm unified-design-system palette, on-fill for
  onPrimary/onError, and inputDecorationTheme/dividerTheme (previously
  unset -> every TextField/Divider fell back to Material defaults).
- slot_selector_row.dart: the Snack ChoiceChip had no explicit
  backgroundColor/side/labelStyle like the hour chips, so it fell through
  to Flutter's own default -- a literal pure-white border.
- Regenerated launcher icon assets (warm charcoal + warm gold accent) via
  python_pkg/app_icons.
- Bump gatelock pin to the released v0.1.1 carrying this same palette.

Verified: flutter analyze clean, diet_guard pytest 443/443 @ 100% coverage,
phone-installed APK pixel-checked (Snack chip border, on-fill contrast).

.pre-commit-config.yaml

@@ -98,7 +98,7 @@ repos:
         additional_dependencies:
           - pytest
           - requests
-          - gatelock @ git+https://github.com/kuhyx/utils@gatelock-v0.1.0#subdirectory=gatelock
+          - gatelock @ git+https://github.com/kuhyx/utils@gatelock-v0.1.1#subdirectory=gatelock
           - crdt-sync @ git+https://github.com/kuhyx/utils@crdt-sync-v0.1.0#subdirectory=crdt-sync
           - mcp
           - pydantic

app/android/app/src/main/res/values/colors.xml

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <color name="ic_launcher_background">#1B1D21</color>
-</resources>
+</resources>

app/assets/icon/icon.svg

@@ -1,8 +1,8 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="1024" height="1024" viewBox="0 0 1024 1024">
-  <rect width="1024" height="1024" fill="#1B1D21"/>
-  <g fill="none" stroke="#26A69A" stroke-width="72" stroke-linecap="round" stroke-linejoin="round" transform="translate(0,-2)">
+  <rect width="1024" height="1024" fill="#211D1B"/>
+  <g fill="none" stroke="#B8862E" stroke-width="72" stroke-linecap="round" stroke-linejoin="round" transform="translate(0,-2)">
     <path d="M 512 275 L 752 366 L 752 544 C 752 655 646 723 512 753 C 378 723 272 655 272 544 L 272 366 Z"/>
-    <g transform="translate(356,362) scale(13)" fill="#26A69A" stroke="none">
+    <g transform="translate(356,362) scale(13)" fill="#B8862E" stroke="none">
       <path d="M11 9H9V2H7v7H5V2H3v7c0 2.12 1.66 3.84 3.75 3.97V22h2.5v-9.03C11.34 12.84 13 11.12 13 9V2h-2v7z"/>
       <path d="M16 12h2.5v10H21V2c-2.76 0-5 2.24-5 5v5z"/>
     </g>

app/assets/icon/icon_foreground.svg

@@ -1,7 +1,7 @@
 <svg xmlns="http://www.w3.org/2000/svg" width="1024" height="1024" viewBox="0 0 1024 1024">
-  <g fill="none" stroke="#26A69A" stroke-width="72" stroke-linecap="round" stroke-linejoin="round" transform="translate(0,-2)">
+  <g fill="none" stroke="#B8862E" stroke-width="72" stroke-linecap="round" stroke-linejoin="round" transform="translate(0,-2)">
     <path d="M 512 275 L 752 366 L 752 544 C 752 655 646 723 512 753 C 378 723 272 655 272 544 L 272 366 Z"/>
-    <g transform="translate(356,362) scale(13)" fill="#26A69A" stroke="none">
+    <g transform="translate(356,362) scale(13)" fill="#B8862E" stroke="none">
       <path d="M11 9H9V2H7v7H5V2H3v7c0 2.12 1.66 3.84 3.75 3.97V22h2.5v-9.03C11.34 12.84 13 11.12 13 9V2h-2v7z"/>
       <path d="M16 12h2.5v10H21V2c-2.76 0-5 2.24-5 5v5z"/>
     </g>

app/lib/ui/theme.dart

@@ -0,0 +1,163 @@
+/// The app's design tokens: one identical palette shared across every one
+/// of kuhy's apps (Flutter, web, Python/Tkinter alike) — see the
+/// `unified-design-system` skill (`~/.claude/skills/unified-design-system/`)
+/// for the frozen token table this file implements. Built from an explicit
+/// `ColorScheme`, not `ColorScheme.fromSeed`, because the shared palette is
+/// hand-picked, not algorithmically derived from one seed color.
+library;
+
+import 'package:flutter/material.dart';
+
+/// Builds the app's single dark `ThemeData` from the shared token set.
+ThemeData buildAppTheme() {
+  const colorScheme = ColorScheme.dark(
+    surface: Color(0xFF211D1B), // ink
+    surfaceContainerHighest: Color(0xFF38312E), // ink-raised-2
+    surfaceContainerHigh: Color(0xFF2B2624), // ink-raised-1
+    onSurface: Color(0xFFECEAE9), // text-on-dark
+    onSurfaceVariant: Color(0xFFAAA09A), // muted-on-dark
+    outline: Color(0xFF463E3A), // line-dark
+    primary: Color(0xFFB8862E), // accent
+    onPrimary: Color(
+      0xFF211D1B,
+    ), // on-fill — every filled surface uses dark text
+    error: Color(0xFFE2585F), // danger
+    onError: Color(0xFF211D1B), // on-fill
+  );
+  return ThemeData(
+    useMaterial3: true,
+    colorScheme: colorScheme,
+    scaffoldBackgroundColor: colorScheme.surface,
+    extensions: const [AppStatusColors.dark],
+    textTheme: const TextTheme(
+      bodyLarge: TextStyle(fontSize: AppTextSize.body),
+      bodyMedium: TextStyle(fontSize: AppTextSize.body),
+      titleLarge: TextStyle(fontSize: AppTextSize.title),
+      titleMedium: TextStyle(fontSize: AppTextSize.subtitle),
+      labelMedium: TextStyle(fontSize: AppTextSize.label),
+      labelSmall: TextStyle(fontSize: AppTextSize.caption),
+    ),
+    // Previously unset, so every TextField fell back to M3's default
+    // indigo focus color instead of the shared palette (open finding from
+    // the unified-design-system component doc).
+    inputDecorationTheme: InputDecorationTheme(
+      filled: true,
+      fillColor: colorScheme.surfaceContainerHigh,
+      border: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(AppRadius.sm),
+        borderSide: BorderSide(color: colorScheme.outline),
+      ),
+      enabledBorder: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(AppRadius.sm),
+        borderSide: BorderSide(color: colorScheme.outline),
+      ),
+      focusedBorder: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(AppRadius.sm),
+        borderSide: BorderSide(color: colorScheme.primary, width: 2),
+      ),
+      labelStyle: TextStyle(color: colorScheme.onSurfaceVariant),
+    ),
+    // Previously unset, so every Divider fell back to M3's default grey
+    // instead of `line-dark` (same open finding as above).
+    dividerTheme: DividerThemeData(
+      color: colorScheme.outline,
+      thickness: 1,
+      space: AppSpacing.md,
+    ),
+  );
+}
+
+/// Semantic status colors M3's [ColorScheme] has no role for (it only has
+/// `error`). Success/warning are the shared `unified-design-system` values —
+/// every status indicator (calendar day, slot chip, sync state) should read
+/// these instead of an ad hoc `Colors.green`/`Colors.amber`.
+@immutable
+class AppStatusColors extends ThemeExtension<AppStatusColors> {
+  /// Creates a status-color set.
+  const AppStatusColors({required this.success, required this.warning});
+
+  /// The shared dark-theme instance — success/warning from the unified
+  /// palette (danger already exists as `colorScheme.error`).
+  static const dark = AppStatusColors(
+    success: Color(0xFF8A9A3C),
+    warning: Color(0xFFE0A63C),
+  );
+
+  /// Positive/on-track status (e.g. a fully-logged, in-budget day).
+  final Color success;
+
+  /// Caution/pending status (e.g. a partially-logged day).
+  final Color warning;
+
+  @override
+  AppStatusColors copyWith({Color? success, Color? warning}) => AppStatusColors(
+    success: success ?? this.success,
+    warning: warning ?? this.warning,
+  );
+
+  @override
+  AppStatusColors lerp(AppStatusColors? other, double t) {
+    if (other is! AppStatusColors) return this;
+    return AppStatusColors(
+      success: Color.lerp(success, other.success, t) ?? success,
+      warning: Color.lerp(warning, other.warning, t) ?? warning,
+    );
+  }
+}
+
+/// Shared spacing scale (4px base) — round any new value to one of these
+/// instead of introducing an off-scale literal.
+abstract final class AppSpacing {
+  /// 4px.
+  static const double xs = 4;
+
+  /// 8px.
+  static const double sm = 8;
+
+  /// 16px.
+  static const double md = 16;
+
+  /// 24px.
+  static const double lg = 24;
+
+  /// 32px.
+  static const double xl = 32;
+
+  /// 48px.
+  static const double xxl = 48;
+}
+
+/// Shared corner-radius scale. Nested radii should be `outer - gap`, not a
+/// fixed constant — compute per instance per safe-design-rules rule 24.
+abstract final class AppRadius {
+  /// Buttons, inputs, chips.
+  static const double sm = 8;
+
+  /// Cards.
+  static const double md = 12;
+
+  /// Sheets, dialogs.
+  static const double lg = 16;
+}
+
+/// Shared type scale (px). `body` is the floor for anything a user reads;
+/// `label`/`caption` are for UI chrome only (timestamps, badges, tags).
+abstract final class AppTextSize {
+  /// 12px — chrome only.
+  static const double caption = 12;
+
+  /// 14px — chrome only.
+  static const double label = 14;
+
+  /// 16px — the floor for actual reading content.
+  static const double body = 16;
+
+  /// 20px.
+  static const double subtitle = 20;
+
+  /// 24px.
+  static const double title = 24;
+
+  /// 32px.
+  static const double display = 32;
+}

app/lib/widgets/slot_selector_row.dart

@@ -4,6 +4,7 @@
 library;
 
 import 'package:diet_guard_app/models/slot.dart';
+import 'package:diet_guard_app/ui/theme.dart';
 import 'package:flutter/material.dart';
 
 /// One row of [ChoiceChip]s: one per today's slot hour plus a fixed
@@ -34,24 +35,42 @@ class SlotSelectorRow extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final scheme = Theme.of(context).colorScheme;
+    final statusColors = Theme.of(context).extension<AppStatusColors>()!;
     final elapsed = elapsedSlots(now).toSet();
+    // Snack has no logged/due/upcoming status like the hour chips, so it
+    // uses `accent` as its "color" instead of a status color -- but still
+    // needs every property below set explicitly like the hour chips are.
+    // Leaving any of them unset falls through to Flutter's own ChoiceChip
+    // default, a literal pure-white border (the one banned value in this
+    // system) -- the open finding the unified-design-system doc flagged.
+    final snackSelected = selectedSlot == null;
+    final snackColor = snackSelected ? scheme.primary : scheme.onSurfaceVariant;
     return Wrap(
-      spacing: 6,
-      runSpacing: 4,
+      spacing: AppSpacing.xs + 2,
+      runSpacing: AppSpacing.xs,
       children: [
         ...daySlots().map((slot) {
           final isLogged = loggedSlots.contains(slot);
           final isDue = !isLogged && elapsed.contains(slot);
           final color = isLogged
-              ? Colors.green
+              ? statusColors.success
               : isDue
-              ? Colors.red
-              : Colors.grey;
+              ? scheme.error
+              : scheme.onSurfaceVariant;
           final isSelected = selectedSlot == slot;
           return ChoiceChip(
             label: Text(slotLabel(slot)),
             selected: isSelected,
-            avatar: isLogged ? Icon(Icons.check, size: 14, color: color) : null,
+            // Icon reads lighter than the label text (rule 28): reduced
+            // opacity instead of the label's full-strength color.
+            avatar: isLogged
+                ? Icon(
+                    Icons.check,
+                    size: 14,
+                    color: color.withValues(alpha: 0.72),
+                  )
+                : null,
             backgroundColor: color.withValues(alpha: 0.15),
             selectedColor: color.withValues(alpha: 0.35),
             labelStyle: TextStyle(color: color),
@@ -64,8 +83,23 @@ class SlotSelectorRow extends StatelessWidget {
         }),
         ChoiceChip(
           label: const Text('Snack'),
-          avatar: const Icon(Icons.fastfood, size: 14),
-          selected: selectedSlot == null,
+          // Icon reads lighter than the label text (rule 28): reduced
+          // opacity instead of the label's full-strength color.
+          avatar: Icon(
+            Icons.fastfood,
+            size: 14,
+            color: snackColor.withValues(alpha: 0.72),
+          ),
+          selected: snackSelected,
+          backgroundColor: scheme.onSurfaceVariant.withValues(alpha: 0.15),
+          selectedColor: scheme.primary.withValues(alpha: 0.35),
+          labelStyle: TextStyle(color: snackColor),
+          side: BorderSide(
+            width: snackSelected ? 2 : 1,
+            color: snackSelected
+                ? snackColor
+                : snackColor.withValues(alpha: 0.4),
+          ),
           onSelected: (_) => onSlotSelected(null),
         ),
       ],

pyproject.toml

@@ -4,7 +4,7 @@ version = "1.0.0"
 description = "Tkinter/systemd log-to-unlock meal gate with calorie/macro budget tracking"
 requires-python = ">=3.10"
 dependencies = [
-    "gatelock @ git+https://github.com/kuhyx/utils@gatelock-v0.1.0#subdirectory=gatelock",
+    "gatelock @ git+https://github.com/kuhyx/utils@gatelock-v0.1.1#subdirectory=gatelock",
     "crdt-sync @ git+https://github.com/kuhyx/utils@crdt-sync-v0.1.0#subdirectory=crdt-sync",
     "requests>=2.31.0",
 ]

requirements.txt

@@ -4,7 +4,7 @@ bandit>=1.7.0
 codespell>=2.2.0
 coverage>=7.4.0
 crdt-sync @ git+https://github.com/kuhyx/utils@crdt-sync-v0.1.0#subdirectory=crdt-sync
-gatelock @ git+https://github.com/kuhyx/utils@gatelock-v0.1.0#subdirectory=gatelock
+gatelock @ git+https://github.com/kuhyx/utils@gatelock-v0.1.1#subdirectory=gatelock
 mcp>=1.9
 mypy>=1.8.0
 pre-commit>=3.6.0