Add NYC subway Transit view

[kyleve]

Posted by an AI agent on kve's behalf.

Stack

• Depends on feat(Throw): add ceiling flight projection app #293.
• This PR targets codex/throw-v1; feat(Throw): add ceiling flight projection app #293 continues to target main.

Summary

• Add NYC Subway as Throw's second runnable projection View, using official MTA schedule data and all eight GTFS-Realtime partitions.
• Estimate assigned trains along scheduled shapes and render typed route lines, train marks, destinations, and contextual stops.
• Preserve bounded last-good partition data during retries.
• Add Transit setup and settings with an independent 2-8 NM map radius, map-center offset, labels, geography, mark size, and network intensity.
• Migrate persisted preferences to version four with exact version-one, version-two, and version-three migration paths.
• Keep the Transit contracts agency-neutral so a later city can provide different schedule and realtime adapters.
• Add generation provenance plus SwiftProtobuf and ZIPFoundation attribution.

Integration with #293

• Keep feat(Throw): add ceiling flight projection app #293's closed runnable catalog, typed projection layer families, prepared Transit provenance, and single presentation-erasure boundary.
• Drive Transit with exact projection activation leases and polling-demand generations.
• Publish Transit through ProjectionPresentationState and VisibleProjection, including request and context freshness checks.
• Persist Transit configuration through the producer-aware, failure-atomic preference transaction path.
• Reject in-flight projection work after worker resets with typed reset tombstones.

Verification

• ./test --no-generate ThrowCoreTests ThrowUITests — 503 tests passed
• ./test --no-generate ThrowTests — 17 tests passed
• ./test --no-generate ThrowUISnapshotTests --record never — 15 tests passed
• ./test --architecture-only — 30 rule tests passed; no violations
• ./swiftformat --lint
• ./sf-symbols --lint
• ./xcstrings --lint
• ./attribution --check
• git diff --check
• Visually reviewed the four refreshed snapshot references before the compare-only pass.