feat: ajout de serveurs depuis l'app + charte flamme sombre

- backend: GET /api/containers (liste lisible), POST/DELETE /api/servers
  (serveurs custom persistés en /data/servers.json, mergés aux intégrés),
  champ custom dans le statut.
- app: écran AddServer (form + sélecteur multi-conteneurs filtrable), FAB
  Ajouter, suppression depuis le détail (serveurs custom only).
- thème: palette flamme/chaud sombre (anthracite + orange→rouge), remplace le
  Material violet/teal par défaut (scaffold, appbar, tabs, boutons, FAB, champs).

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

lib/theme.dart

@@ -1,42 +1,128 @@
 import 'package:flutter/material.dart';
 
-/// Thèmes Material 3 (clair + sombre) avec un accent unifié.
+/// Thème « flamme / chaud sombre » — anthracite + accents orange→rouge.
+/// Remplace la palette Material par défaut (violet/teal).
 class AppTheme {
-  static const _seed = Color(0xFF5E5CE6);
+  // Palette
+  static const bg = Color(0xFF14110F); // fond anthracite
+  static const surface1 = Color(0xFF1F1B18); // cartes / champs
+  static const surface2 = Color(0xFF262119); // éléments surélevés
+  static const flame = Color(0xFFFF7A18); // orange accent
+  static const ember = Color(0xFFFF3D00); // rouge braise
+  static const ink = Color(0xFFF5EFE9); // texte principal
+  static const inkMuted = Color(0xFFA89F97); // texte secondaire
 
-  static ThemeData light() => _base(Brightness.light);
-  static ThemeData dark() => _base(Brightness.dark);
+  static ThemeData light() => dark(); // app pensée sombre → même thème
+  static ThemeData dark() {
+    const scheme = ColorScheme(
+      brightness: Brightness.dark,
+      primary: flame,
+      onPrimary: Color(0xFF230F00),
+      primaryContainer: Color(0xFF3A2410),
+      onPrimaryContainer: Color(0xFFFFD9B8),
+      secondary: ember,
+      onSecondary: Colors.white,
+      secondaryContainer: Color(0xFF4A1A0A),
+      onSecondaryContainer: Color(0xFFFFD5C8),
+      tertiary: Color(0xFFFFB74D),
+      onTertiary: Color(0xFF241400),
+      error: Color(0xFFFF6B5E),
+      onError: Color(0xFF3A0A05),
+      surface: bg,
+      onSurface: ink,
+      surfaceContainerLowest: Color(0xFF0F0D0B),
+      surfaceContainerLow: surface1,
+      surfaceContainer: surface1,
+      surfaceContainerHigh: surface2,
+      surfaceContainerHighest: Color(0xFF2E2820),
+      onSurfaceVariant: inkMuted,
+      outline: Color(0xFF4A433D),
+      outlineVariant: Color(0xFF332E29),
+      inverseSurface: ink,
+      onInverseSurface: bg,
+      shadow: Colors.black,
+      scrim: Colors.black,
+    );
 
-  static ThemeData _base(Brightness brightness) {
-    final scheme = ColorScheme.fromSeed(seedColor: _seed, brightness: brightness);
     return ThemeData(
       useMaterial3: true,
       colorScheme: scheme,
-      scaffoldBackgroundColor: scheme.surface,
-      appBarTheme: AppBarTheme(
-        backgroundColor: scheme.surface,
-        foregroundColor: scheme.onSurface,
+      scaffoldBackgroundColor: bg,
+      canvasColor: bg,
+      appBarTheme: const AppBarTheme(
+        backgroundColor: bg,
+        foregroundColor: ink,
         centerTitle: false,
         elevation: 0,
+        scrolledUnderElevation: 0,
         titleTextStyle: TextStyle(
-          color: scheme.onSurface,
+          color: ink,
           fontSize: 24,
           fontWeight: FontWeight.w800,
           letterSpacing: -0.5,
         ),
       ),
       cardTheme: CardTheme(
+        color: surface1,
         clipBehavior: Clip.antiAlias,
         shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(22)),
         elevation: 0,
       ),
+      tabBarTheme: const TabBarTheme(
+        labelColor: flame,
+        unselectedLabelColor: inkMuted,
+        indicatorColor: flame,
+        dividerColor: Colors.transparent,
+        labelStyle: TextStyle(fontWeight: FontWeight.w700),
+      ),
       filledButtonTheme: FilledButtonThemeData(
         style: FilledButton.styleFrom(
+          backgroundColor: flame,
+          foregroundColor: const Color(0xFF230F00),
           shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
           padding: const EdgeInsets.symmetric(horizontal: 22, vertical: 14),
           textStyle: const TextStyle(fontWeight: FontWeight.w700, fontSize: 15),
         ),
       ),
+      outlinedButtonTheme: OutlinedButtonThemeData(
+        style: OutlinedButton.styleFrom(
+          foregroundColor: ink,
+          side: const BorderSide(color: Color(0xFF4A433D)),
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
+        ),
+      ),
+      floatingActionButtonTheme: const FloatingActionButtonThemeData(
+        backgroundColor: flame,
+        foregroundColor: Color(0xFF230F00),
+      ),
+      inputDecorationTheme: InputDecorationTheme(
+        filled: true,
+        fillColor: surface1,
+        border: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: BorderSide.none,
+        ),
+        enabledBorder: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: const BorderSide(color: Color(0xFF332E29)),
+        ),
+        focusedBorder: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: const BorderSide(color: flame, width: 2),
+        ),
+        labelStyle: const TextStyle(color: inkMuted),
+      ),
+      progressIndicatorTheme: const ProgressIndicatorThemeData(
+        color: flame,
+        linearTrackColor: Color(0xFF332E29),
+      ),
+      dividerTheme: const DividerThemeData(color: Color(0xFF332E29)),
+      snackBarTheme: const SnackBarThemeData(
+        backgroundColor: surface2,
+        contentTextStyle: TextStyle(color: ink),
+      ),
+      dialogTheme: const DialogTheme(backgroundColor: surface1),
+      chipTheme: const ChipThemeData(backgroundColor: surface2),
     );
   }
 }