chore(branding): rebrand FixMate to CityPulse across codebase

- Update product name in README, backend docs, and design tokens
- Rename Flutter root widget to CityPulseApp and update tests
- Update dashboard brand strings and HTML title
- Refresh i18n strings (en/ms) and welcome taglines
- Adjust backend API title/description and root message
- Minor formatting in ApiService comments; no logic changes
- Update Android/iOS manifest comments and pubspec description

No API endpoints or response schema changes.

assets/lang/ms.json

@@ -1,5 +1,5 @@
 {
-  "app.name": "FixMate",
+  "app.name": "CityPulse",
   "nav.report": "Lapor",
   "nav.map": "Peta",
   "nav.myReports": "Laporan Saya",
@@ -88,7 +88,7 @@
   "cta.skip": "Langkau",
   "cta.next": "Seterusnya",
   "cta.getStarted": "Mula",
-  "onboarding.header": "Selamat datang ke FixMate",
+  "onboarding.header": "Selamat datang ke CityPulse",
   "onboarding.title1": "Tangkap pantas",
   "onboarding.body1": "Ambil gambar dan hantar dalam kurang satu minit.",
   "onboarding.title2": "Peta yang jelas",
@@ -104,7 +104,7 @@
   "cta.continueGuest": "Teruskan sebagai Tetamu",
   "cta.signIn": "Log Masuk",
   "cta.skip": "Langkau buat masa ini",
-  "onboarding.header": "Selamat Datang ke FixMate",
+  "onboarding.header": "Selamat Datang ke CityPulse",
   "onboarding.title1": "Laporan Isu Pantas",
   "onboarding.subtitle1": "Pengesanan Berkuasa AI",
   "onboarding.body1": "Hanya ambil gambar mana-mana isu bandar - AI kami secara automatik mengenal pasti dan mengkategorikan masalah dalam beberapa saat.",