Add Micro Gains: iOS app + Cloudflare Worker

[zackbart]

Summary

• New app micro-gains/: a UIKit iPhone app that pings you a few times a day with one tiny bodyweight set, plus a Cloudflare Worker + D1 backend for settings, set log, streaks/history and the exercise catalog.
• Scheduling is on-device (local notifications, deterministic DST-safe scheduler filling the 64-request budget ~2 weeks out). Auth is a device UUID header, same posture as Read the Bible.
• Defaults and selection rules come from RESEARCH.md (exercise snacks, greasing the groove, sedentary-break trials, notification decay).

Verification

• iOS: 104 unit tests green (xcodebuild ... -destination 'iPhone 17' test); scheduler, store, sync, codec, DST, budget.
• Worker: 124 tests green against a real local D1 via vitest-pool-workers; deployed at https://micro-gains.onemany.workers.dev.
• Simulator: fresh install schedules 60 reminders; a notification Done action logged a set that synced into D1. Release build talks to production.
• Two Codex reviews (spec + code), all findings fixed; UI QA across iPhone 16e / 17 Pro Max at default and accessibility type sizes.
• TestFlight build 0.0.1 (1) uploaded and added to the Internal Testers group.

🤖 Generated with Claude Code