refactor(swift): replace build scripts with xtask

[Dzejkop]

Summary

• replace Swift shell scripts with cargo xtask swift commands
• update CI, release workflows, local tooling, and docs

Testing

• cargo clippy -p xtask --all-targets -- -D warnings
• cargo test -p xtask
• full iOS build and Swift foreign-binding test

---

Note

Medium Risk
Touches iOS XCFramework build and release packaging paths used in production Swift distribution, though behavior is largely a straight port from the removed scripts.

Overview
Moves Swift/iOS automation from deleted swift/*.sh scripts into cargo xtask swift (build, test, local, archive), aligned with the existing Kotlin xtask pattern.

CI and release now invoke cargo xtask swift build, cargo xtask swift test --skip-build, and cargo xtask swift archive instead of shell entrypoints; the Swift test matrix job also sets up Rust so xtask can run. Release workflow notes that WALLETKIT_CARGO_FEATURES applies to both Kotlin and Swift builds.

Docs and helpers point at the new commands (root README, swift/README.md, Nix docs); make_local_swift_package.sh calls cargo xtask swift local. Local SPM output stays under swift/local_build/walletkit-swift.

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[Dzejkop]

/otto --modle=opus review this PR

[agentotto]

Kicked off a thorough review of PR #455 using Opus with a workspace to inspect the full diff and check behavior parity between the removed shell scripts and the new xtask swift commands. It'll post inline comments plus a summary verdict directly on the PR — I'll let you know once it's done.

[agentotto]

Minor CI efficiency: unlike the sibling swift-build job, this swift-test matrix job doesn't add a Swatinem/rust-cache step, so cargo xtask swift test --skip-build recompiles xtask and all its deps from scratch on each of the 5 Xcode matrix entries (the uploaded artifact only contains WalletKit.xcframework + Sources, not target/). Adding a rust-cache step here would cut redundant compile time. Not blocking.

[agentotto]

Review summary — ✅ Approve (one minor, non-blocking inline note)

I checked out refactor/swift-xtask, diffed each new xtask module against the shell scripts it replaces, and ran cargo check -p xtask + cargo test -p xtask (all 8 tests pass).

Behavior parity verified — the ports are faithful:

• build: same iOS targets, IPHONEOS_DEPLOYMENT_TARGET, AWS_LC_SYS_CFLAGS/RUSTFLAGS workaround, lipo universal-sim step, uniffi bindgen invocation, module → framework module modulemap rewrite, and Info.plist contents all match build_swift.sh/make_walletkit_framework.sh.
• test: SDK check, generated-sources copy, DerivedData cleanup, simulator selection (iPhone 16 → any iPhone), and CI-only erase/boot/bootstatus hygiene all match run_swift_tests.sh. Result detection now relies on xcodebuild's exit code rather than grepping the log — this is more robust than the old string-matching and removes a false-positive/negative risk.
• local/archive: output layout (swift/local_build/walletkit-swift) and Package.swift template substitution match local_swift.sh/archive_swift.sh, with added empty-arg validation.

Other checks:

• Relative paths in the xtask are anchored via sh.change_dir(workspace_root()) in main.rs, so cargo xtask swift … works regardless of the invoking cwd — the cd "$PROJECT_ROOT" added to make_local_swift_package.sh is harmless but not strictly required.
• No dangling references to any of the deleted swift/*.sh scripts remain anywhere in the repo.
• CI/release YAML swaps are consistent; swift-test correctly adds a Rust setup step (needed now that the entrypoint is cargo xtask), and --skip-build avoids requiring nargo/iOS targets in that job.

One behavior change worth calling out (intentional & documented, not a bug): the old build_swift.sh hardcoded compress-zkeys,embed-zkeys,v3 and ignored WALLETKIT_CARGO_FEATURES. The xtask now reads WALLETKIT_CARGO_FEATURES (falling back to that same default), so the release workflow's env var now also drives the iOS build — which matches the updated comment ("Used by both the Kotlin and Swift xtasks"). Output is identical today since the values coincide; just be aware that changing that env var in the release workflow will now affect iOS too.

Nice cleanup overall — good alignment with the existing Kotlin xtask pattern, solid error messages, and useful unit tests around the pure logic (path resolution, manifest rendering, simulator-ID parsing).

[agentotto]

Review complete on PR #455 (worldcoin/walletkit).

Verdict: ✅ Approve (one minor, non-blocking note)

The subagent checked out the branch, compared each new xtask module against the shell script it replaces, and ran cargo check/cargo test -p xtask (8/8 passing). Behavior parity across build, test, local, and archive looked solid, with no dangling references to the deleted scripts.

Posted to the PR:

• Inline comment on ci.yml: the swift-test matrix job is missing a Swatinem/rust-cache step, so xtask recompiles from scratch across all 5 Xcode matrix runs — minor CI efficiency issue, not blocking.
• Summary comment: overall approval, plus a flag that WALLETKIT_CARGO_FEATURES now also drives the iOS build (previously ignored) — output is currently identical but worth being aware of.

No correctness bugs or parity gaps found.