feat: brand retheme to m8chat.au blues, fix black logo, v1.6.0+8

- m8logo.svg: inline fills (flutter_svg ignores <style> blocks; logo rendered black)
- theme.dart v2.0.0: purple -> site palette (#1265ED / #3B8BFF / navy darks)
- app_config.dart: appVersion 1.3.0 -> 1.6.0 (profile screen showed stale version)
- manifest.json: theme/background colours to match
- Remove em-dashes from user-visible UI strings (global style rule)
- chat_screen.dart: fix use_build_context_synchronously in _leaveRoom
- Deployed to app2.m8chat.au after full functionality audit (all green)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/app/theme.dart

@@ -1,25 +1,27 @@
-// Version: 1.0.0 | Created: 2026-04-01
+// Version: 2.0.0 | Created: 2026-04-01 | Updated: 2026-07-03
 // M8Chat brand theme — dark and light variants.
-// Primary brand colour: #5C35C9 (deep purple). Accent: #7B5CF6.
+// Palette from the m8chat.au Elementor kit (kit post 8):
+//   Accent #1 "#1265ED", Blue Element "#3B8BFF", Ancop Blue "#010B46".
+// v2.0.0 replaces the old purple scheme, which did not match the website.
 
 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 brandBlue = Color(0xFF1265ED);
+  static const Color accentBlue = Color(0xFF3B8BFF);
+  static const Color darkBackground = Color(0xFF0A0F2E);
+  static const Color darkSurface = Color(0xFF131A42);
+  static const Color darkSurfaceVariant = Color(0xFF1C2452);
+  static const Color onDarkSurface = Color(0xFFE8ECF5);
+  static const Color subtleText = Color(0xFF96A0C2);
   static const Color errorRed = Color(0xFFCF6679);
   static const Color unreadGreen = Color(0xFF4CAF50);
 }
 
 /// Dark theme — default for M8Chat.
 ThemeData buildDarkTheme() {
-  const seed = M8Colours.brandPurple;
+  const seed = M8Colours.brandBlue;
 
   final scheme =
       ColorScheme.fromSeed(
@@ -28,7 +30,7 @@ ThemeData buildDarkTheme() {
       ).copyWith(
         surface: M8Colours.darkBackground,
         surfaceContainerHighest: M8Colours.darkSurface,
-        primary: M8Colours.accentPurple,
+        primary: M8Colours.accentBlue,
         onSurface: M8Colours.onDarkSurface,
         error: M8Colours.errorRed,
       );
@@ -45,7 +47,7 @@ ThemeData buildDarkTheme() {
     ),
     navigationBarTheme: NavigationBarThemeData(
       backgroundColor: M8Colours.darkSurface,
-      indicatorColor: M8Colours.accentPurple.withAlpha(51),
+      indicatorColor: M8Colours.accentBlue.withAlpha(51),
       labelTextStyle: WidgetStateProperty.all(
         const TextStyle(fontSize: 12, color: M8Colours.onDarkSurface),
       ),
@@ -59,14 +61,14 @@ ThemeData buildDarkTheme() {
       ),
       focusedBorder: OutlineInputBorder(
         borderRadius: BorderRadius.circular(12),
-        borderSide: const BorderSide(color: M8Colours.accentPurple, width: 2),
+        borderSide: const BorderSide(color: M8Colours.accentBlue, width: 2),
       ),
       labelStyle: const TextStyle(color: M8Colours.subtleText),
       hintStyle: const TextStyle(color: M8Colours.subtleText),
     ),
     elevatedButtonTheme: ElevatedButtonThemeData(
       style: ElevatedButton.styleFrom(
-        backgroundColor: M8Colours.accentPurple,
+        backgroundColor: M8Colours.accentBlue,
         foregroundColor: Colors.white,
         minimumSize: const Size.fromHeight(52),
         shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
@@ -97,7 +99,7 @@ ThemeData buildDarkTheme() {
 
 /// Light theme — follows system preference if user selects it.
 ThemeData buildLightTheme() {
-  const seed = M8Colours.brandPurple;
+  const seed = M8Colours.brandBlue;
 
   final scheme = ColorScheme.fromSeed(
     seedColor: seed,