feat: add Wallet Apps bridge adapter for iframe wallet mode

[marsiandeployer]

Summary

• add wallet-apps-bridge-client.js (EIP-1193 provider bridge over postMessage)
• inject bridge client in index.html before app bootstrap
• add integration docs in README.md
• enable allowAnyHostOrigin by default for faster QA across many wallet host domains
  • accepts https://*, http://localhost*, http://127.0.0.1*
  • can be restricted by setting window.SO_DefinanceBridgeConfig.allowAnyHostOrigin = false + allowedHostOrigins

Why

Needed for MultiCurrencyWallet #/apps embedded mode so DEX connect button uses host wallet via bridge.

Test

• open with ?walletBridge=swaponline
• verify window.ethereum.request({ method: "eth_requestAccounts" })
• verify bridge works on different wallet host domains without allowlist edits

Related: swaponline/MultiCurrencyWallet#5268
Closes #32

[marsiandeployer]

Update: for current development/testing we use https://dex.onout.org with this bridge-enabled build.