Mitra Profil: WA/TG contacts + Keluar-only (no Hapus Akun)

Replaces the placeholder "Hubungi Koordinator" row with two real
contacts pulled from backend config (support_handles_json), and drops
the "Hapus Akun" CTA. Mirrors the figma BestieProfile design but uses
the same WA/TG channel as the customer Tanya Admin sheet — business
decided the same ops team triages both audiences.

Backend:
- Promote support-handles route from /api/client to /api/shared
  (renamed file + export). Both apps now consume the same endpoint;
  hitting /api/client/* from mitra would violate the per-app
  convention in mitra_app/CLAUDE.md.
- client_app provider updated to /api/shared/support-handles.

Mitra app:
- New support_handles_provider mirroring the client_app one. Adds a
  `displayHandle` getter that strips the URL scheme for the subtitle
  ("https://wa.me/X" → "wa.me/X", "https://t.me/Y" → "t.me/Y") so the
  row looks like the figma without exposing raw URLs.
- Profil screen now lists: Chat WhatsApp Kami, Chat Telegram Kami,
  Syarat & Ketentuan, Kebijakan Privasi. Danger zone simplified to
  Keluar only — mitras request account deletion through the same
  WA/TG channels (no separate self-service path).
- url_launcher added as a runtime dep, launches deeplinks in
  externalApplication mode with graceful snackbar fallback when
  parsing or launching fails.

Updates [[feedback-mitra-internal-audience]] — pre-login rule still
holds (no admin CTAs on S3a/S3b/AccountInactive), but the post-login
Profil tab now does surface WA/TG. Overrides decided 2026-05-21.

Verified on emulator-5556: Profil tab renders both rows with handles
from `wa.me/6285173310010` + `t.me/halobestie`, Keluar present, no
Hapus Akun button.

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

mitra_app/pubspec.lock

@@ -1004,6 +1004,70 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  url_launcher:
+    dependency: "direct main"
+    description:
+      name: url_launcher
+      sha256: f6a7e5c4835bb4e3026a04793a4199ca2d14c739ec378fdfe23fc8075d0439f8
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.2"
+  url_launcher_android:
+    dependency: transitive
+    description:
+      name: url_launcher_android
+      sha256: "17bc677f0b301615530dd1d67e0a9828cafa2d0b6b6eae4cd3679b7eac4a273c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.30"
+  url_launcher_ios:
+    dependency: transitive
+    description:
+      name: url_launcher_ios
+      sha256: "580fe5dfb51671ae38191d316e027f6b76272b026370708c2d898799750a02b0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.4.1"
+  url_launcher_linux:
+    dependency: transitive
+    description:
+      name: url_launcher_linux
+      sha256: d5e14138b3bc193a0f63c10a53c94b91d399df0512b1f29b94a043db7482384a
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.2"
+  url_launcher_macos:
+    dependency: transitive
+    description:
+      name: url_launcher_macos
+      sha256: "368adf46f71ad3c21b8f06614adb38346f193f3a59ba8fe9a2fd74133070ba18"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.5"
+  url_launcher_platform_interface:
+    dependency: transitive
+    description:
+      name: url_launcher_platform_interface
+      sha256: "552f8a1e663569be95a8190206a38187b531910283c3e982193e4f2733f01029"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.2"
+  url_launcher_web:
+    dependency: transitive
+    description:
+      name: url_launcher_web
+      sha256: "85c81589622fbc87c1c683aaea164d3604a7777495a79d91e39ffcdec39ddb34"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.4.3"
+  url_launcher_windows:
+    dependency: transitive
+    description:
+      name: url_launcher_windows
+      sha256: "712c70ab1b99744ff066053cbe3e80c73332b38d46e5e945c98689b2e66fc15f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.5"
   uuid:
     dependency: transitive
     description: