feat(branding): rebranding WhatSMS + tradução PT-PT

- applicationId: me.capcom.smsgateway → pt.whatsms.gateway
  (namespace Java interno mantido para minimizar risco de refactor)
- app_name: SMSGate → WhatSMS Gateway
- Ícone adaptativo: vector foreground + mipmap-anydpi-v26 copiados do
  whatsms-gateway v2.1 (logo WhatSMS verde)
- ic_launcher_background: #AEADAB → #25D366 (verde WhatSMS)
- values-pt-rPT/strings.xml: tradução completa (~130 strings)

Base branding + PT-PT. Ainda falta:
- Hardcode server URL smsgw.whatsms.pt (Fase 3 do fork)
- SIM selector no UI (Fase 4 do fork)
- Build signed com whatsms-release.jks

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/build.gradle

@@ -9,7 +9,7 @@ android {
     compileSdk 33
 
     defaultConfig {
-        applicationId "me.capcom.smsgateway"
+        applicationId "pt.whatsms.gateway"
         minSdk 21
         targetSdk 33
         versionCode 1