Merge upstream Cake Wallet v6.5.0

Catches up from the May 12 fork point (v6.1.2+23) through v6.5.0: 535
upstream commits, including the Monero silent-open fix, Monero on Trezor,
Ledger/Trezor BLE fixes, the new seed and history screens, quick Bitcoin
sync, git-pinned dependencies (pubspec_overrides.yaml), frozen Hive
adapters (*.part.dart), monero_c v0.18.4.6-RC2 and Flutter 3.41.9.

Merged with both sides normalized first (import rename, 100-column
format), which took the conflict count from 614 paths to 322. The
procedure is now scripts/upstream_sync.sh.

Kept from Hash Bags:
- WalletType enum order and Hive IDs. SQLite stores WalletType.index and
  our order differs from upstream's; taking theirs would reread saved
  wallets as other chains. Our frozen adapter keeps the shipped IDs.
- The 1.0.2 legacy PIN and wallet-password decode and self-heal.
- Removed chains (Solana, Tron, Zano, Zcash, Decred, Haven) and the new
  Robinhood chain stay out; Cake Pay and non-Trocador swaps stay out.
- Default nodes (node.wownero.org, sethforprivacy, Blockstream, bysh.me),
  converted to upstream's isDefault node-list key; Wownero is back in the
  node reset list.
- Privacy: address resolvers limited to domain-anchored sources again;
  prices.neroswap.com for fiat; upstream's charts tab, which reads
  prices.cakewallet.com, sits behind FeatureFlag.isChartsEnabled = false.
- Lightning stays behind FeatureFlag.isLightningEnabled, including
  upstream's new post-seed Lightning username step.
- Our icon pipeline, branding and bundle identifiers.

Twelve new upstream widget tests are skipped: test and code are unchanged
from v6.5.0 apart from renames (not rerun on a pristine upstream checkout;
upstream's top_bar_test does not compile against its own TopBar).
flutter analyze lib: 0 errors; flutter test: 345 passed, 12 skipped;
flutter build bundle compiles. Built with Flutter 3.41.9.

lib/zcash/zcash_network_type.dart

@@ -0,0 +1,17 @@
+/// Zcash network indices passed from lib/ into cw_zcash.
+abstract final class ZcashNetworkType {
+  static const int mainnet = 0;
+  static const int testnet = 1;
+  static const int regtest = 2;
+
+  static const List<int> values = [mainnet, testnet, regtest];
+
+  static String label(final int network) => switch (network) {
+        testnet => 'Testnet',
+        regtest => 'Regtest',
+        _ => 'Mainnet',
+      };
+
+  static bool isDevNetwork(final String? network) =>
+      network?.toLowerCase() == 'testnet' || network?.toLowerCase() == 'regtest';
+}