[codex] Preserve dapp launch parameters

[Jim8y]

Summary

• Add a shared dApp launch URI helper for OneGate app-link validation and parameter merging.
• Preserve query strings and fragments from OneGate QR/deep links when opening the real dApp URL.
• Keep pasted https://onegate.space/app/{id}?… links in dApp search from dropping launch parameters.

Root Cause

The QR/deep-link path carried the original URI in some Android cases, but final WebView URL construction only appended uri.Query directly and ignored fragments or existing dApp query strings. Search results also converted app links back to plain DApp objects, losing the original launch URI.

Validation

• git diff --check
• dotnet build OneGateApp/OneGateApp.csproj -f net10.0-android
• dotnet build OneGateApp/OneGateApp.csproj -f net10.0-maccatalyst -p:ValidateXcodeVersion=false

Note: MacCatalyst build succeeds with the existing local provisioning-profile warning for associated domains.