Add Trails Actions iOS example

[tolgahan-arikan]

Summary

• Adds a standalone iOS SwiftUI trails-actions example app.
• Includes the generated Trails API Swift client from 0xsequence/trails-api, generated locally with ../gen-swift.
• Verifies the generated client by loading Earn pools from GetEarnPools in the simulator.
• Sets this up as prep work for a Swift example with functionality similar to ../typescript-sdk/examples/trails-actions, while using the Trails API directly because the 0xtrails/actions composition layer exists only in TypeScript today.

Suggested API path for next flows

• POL -> USDC swap on Polygon: use QuoteIntent with Polygon as origin and destination, POL/native as the origin token, Polygon USDC as the destination token, and .exactInput, then continue with CommitIntent and ExecuteIntent once wallet signing/submission is wired in.
• USDC deposit on Polygon: use YieldGetMarkets to find an enterable Polygon USDC market, then YieldCreateEnterAction with CreateYieldActionRequest(earnMarketId:userWalletAddress:args:); submit the returned unsigned transactions through the wallet layer.
• Swap + deposit: first select the USDC earn market with YieldGetMarkets; longer term, either quote a POL -> USDC QuoteIntent whose destination call targets the earn deposit call data or add a small Swift encoder equivalent to TypeScript resolveActionsToCalls for wrap, swap, and earn deposit. Until that exists, use the API-only two-step path: QuoteIntent/CommitIntent/ExecuteIntent, then YieldCreateEnterAction.

Test Plan

• xcodebuild -project Examples/trails-actions/trails-actions.xcodeproj -scheme trails-actions -destination "platform=iOS Simulator,id=7E2BF282-B838-40E1-8A9E-57F17F8A7211" -derivedDataPath /tmp/trails-actions-derived CODE_SIGNING_ALLOWED=NO build
• Installed and launched on the iPhone 17 simulator; verified the app displayed Earn API loaded with 94 pools returned.
• swift test
• Ran generated/example output path scan; no local machine paths were found.