Hosts: serve funding to the core #1267

The host serves the funding modality to the core.

• set_funding_callbacks: present_funding opens the overlay on the direction's screen; present_provider_frame shows the provider's App route in a host-owned bottom sheet and answers Closed or Dismissed; funding_session_changed drives the pill and the history store

• Confirm in the overlay calls select_funding_provider; cancel calls cancel_funding

• acknowledge_funding_session once the history row is written

• Start the provider's worker when the core holds it (iOS: iOS: run workers from the core ledger #1146)

• Open the overlay from the CASH card with open_funding, and remove the getcash launch: iOS FundingDomainProvider, RampAction, openRampProduct; Android DigitalDollarCardDetailsViewModel openSpaSheet(onrampUrl), RemoteConfigFundingDomainProvider and its uses (WhitelistedProductsProvider, ProductDeepLinkGate, FundingProductsWarmUp); the funding_config remote-config key

• Read Worker manifests through the core (worker_manifest, feat(truapi): read worker manifests for hosts #1283) instead of the host parsers (Android ManifestParser, iOS ProductManifestParser), which do not read includes.funding

• iOS

• Android

Done when A product's session reaches the provider's worker and ends as one history row, on both platforms.
Depends on #1142, #1145
Refs NativeFundingCallbacks · RUNTIME.md FundingPlatform