Strip remaining cakewallet.com endpoints + delete Monerocom assets

- Stub dashboard bulletin (was polling service-api.cakewallet.com); returns
  empty ServicesResponse until we stand up our own notice service.
- Repoint changelog 'View more info' link to hash.boats (modal trigger
  remains disabled; this is just for when we re-enable it).
- Replace exchange-helper.cakewallet.com with exchange-helper.such.software
  in moonpay/robinhood/onramper providers. Buy providers are still dormant
  (empty getAvailable*ProviderTypes); URL change is a fail-loudly placeholder
  to ensure we stand up our own proxy before re-enabling any of them.
- Delete Monerocom_Terms_of_Use.txt and Monerocom_Release_Notes.txt — these
  were Cake's Monero.com brand variant, never used by Hash Wallet. Collapse
  the isMoneroOnly branch in disclaimer_page.dart to always load
  Terms_of_Use.txt.
- Add docs/links.md (gitignored) inventorying all public-facing URLs and
  emails shipped in the binary.

lib/src/screens/disclaimer/disclaimer_page.dart

@@ -4,7 +4,6 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:hash_wallet/src/screens/base_page.dart';
 import 'package:hash_wallet/src/widgets/primary_button.dart';
-import 'package:hash_wallet/wallet_type_utils.dart';
 import 'package:modal_bottom_sheet/modal_bottom_sheet.dart';
 
 class DisclaimerPage extends BasePage {
@@ -36,8 +35,7 @@ class DisclaimerBodyState extends State<DisclaimerPageBody> {
   String _fileText = '';
 
   void getFileLines() {
-    final fileName =
-        isMoneroOnly ? 'assets/text/Monerocom_Terms_of_Use.txt' : 'assets/text/Terms_of_Use.txt';
+    const fileName = 'assets/text/Terms_of_Use.txt';
     rootBundle.loadString(fileName).then((text) => setState(() => _fileText = text));
   }