feat: Phase 1 complete — Matrix login, rooms, chat, profile

- Direct m.login.password auth against matrix.m8chat.au
- Room list with unread badges, last message, timestamps
- Chat timeline (text, images, files, replies, reactions)
- Profile screen with expandable Notifications and Security sections
- Olm E2EE initialisation (web WASM bootstrap)
- Global error handler preventing Matrix SDK crashes
- GoRouter with refreshListenable (no recreation on auth change)
- Feature-first clean architecture: Riverpod + GoRouter + Drift
- Deployed to https://app2.m8chat.au

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/app/theme.dart

@@ -0,0 +1,137 @@
+// Version: 1.0.0 | Created: 2026-04-01
+// M8Chat brand theme — dark and light variants.
+// Primary brand colour: #5C35C9 (deep purple). Accent: #7B5CF6.
+
+import 'package:flutter/material.dart';
+
+/// M8Chat brand colours.
+abstract final class M8Colours {
+  static const Color brandPurple = Color(0xFF5C35C9);
+  static const Color accentPurple = Color(0xFF7B5CF6);
+  static const Color darkBackground = Color(0xFF0F0F1A);
+  static const Color darkSurface = Color(0xFF1A1A2E);
+  static const Color darkSurfaceVariant = Color(0xFF22223A);
+  static const Color onDarkSurface = Color(0xFFE8E8F0);
+  static const Color subtleText = Color(0xFF9898B0);
+  static const Color errorRed = Color(0xFFCF6679);
+  static const Color unreadGreen = Color(0xFF4CAF50);
+}
+
+/// Dark theme — default for M8Chat.
+ThemeData buildDarkTheme() {
+  const seed = M8Colours.brandPurple;
+
+  final scheme =
+      ColorScheme.fromSeed(
+        seedColor: seed,
+        brightness: Brightness.dark,
+      ).copyWith(
+        surface: M8Colours.darkBackground,
+        surfaceContainerHighest: M8Colours.darkSurface,
+        primary: M8Colours.accentPurple,
+        onSurface: M8Colours.onDarkSurface,
+        error: M8Colours.errorRed,
+      );
+
+  return ThemeData(
+    useMaterial3: true,
+    colorScheme: scheme,
+    scaffoldBackgroundColor: M8Colours.darkBackground,
+    appBarTheme: AppBarTheme(
+      backgroundColor: M8Colours.darkSurface,
+      foregroundColor: M8Colours.onDarkSurface,
+      elevation: 0,
+      surfaceTintColor: Colors.transparent,
+    ),
+    navigationBarTheme: NavigationBarThemeData(
+      backgroundColor: M8Colours.darkSurface,
+      indicatorColor: M8Colours.accentPurple.withAlpha(51),
+      labelTextStyle: WidgetStateProperty.all(
+        const TextStyle(fontSize: 12, color: M8Colours.onDarkSurface),
+      ),
+    ),
+    inputDecorationTheme: InputDecorationTheme(
+      filled: true,
+      fillColor: M8Colours.darkSurfaceVariant,
+      border: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(12),
+        borderSide: BorderSide.none,
+      ),
+      focusedBorder: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(12),
+        borderSide: const BorderSide(color: M8Colours.accentPurple, width: 2),
+      ),
+      labelStyle: const TextStyle(color: M8Colours.subtleText),
+      hintStyle: const TextStyle(color: M8Colours.subtleText),
+    ),
+    elevatedButtonTheme: ElevatedButtonThemeData(
+      style: ElevatedButton.styleFrom(
+        backgroundColor: M8Colours.accentPurple,
+        foregroundColor: Colors.white,
+        minimumSize: const Size.fromHeight(52),
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+        textStyle: const TextStyle(
+          fontSize: 16,
+          fontWeight: FontWeight.w600,
+          letterSpacing: 0.5,
+        ),
+      ),
+    ),
+    cardTheme: CardThemeData(
+      color: M8Colours.darkSurface,
+      elevation: 0,
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+    ),
+    dividerTheme: const DividerThemeData(
+      color: M8Colours.darkSurfaceVariant,
+      thickness: 1,
+    ),
+    snackBarTheme: SnackBarThemeData(
+      backgroundColor: M8Colours.darkSurfaceVariant,
+      contentTextStyle: const TextStyle(color: M8Colours.onDarkSurface),
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
+      behavior: SnackBarBehavior.floating,
+    ),
+  );
+}
+
+/// Light theme — follows system preference if user selects it.
+ThemeData buildLightTheme() {
+  const seed = M8Colours.brandPurple;
+
+  final scheme = ColorScheme.fromSeed(
+    seedColor: seed,
+    brightness: Brightness.light,
+  );
+
+  return ThemeData(
+    useMaterial3: true,
+    colorScheme: scheme,
+    elevatedButtonTheme: ElevatedButtonThemeData(
+      style: ElevatedButton.styleFrom(
+        minimumSize: const Size.fromHeight(52),
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+        textStyle: const TextStyle(
+          fontSize: 16,
+          fontWeight: FontWeight.w600,
+          letterSpacing: 0.5,
+        ),
+      ),
+    ),
+    inputDecorationTheme: InputDecorationTheme(
+      filled: true,
+      border: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(12),
+        borderSide: BorderSide.none,
+      ),
+      focusedBorder: OutlineInputBorder(
+        borderRadius: BorderRadius.circular(12),
+        borderSide: BorderSide(color: scheme.primary, width: 2),
+      ),
+    ),
+    snackBarTheme: SnackBarThemeData(
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
+      behavior: SnackBarBehavior.floating,
+    ),
+  );
+}