Enforce deterministic, warning-free builds

[robinebers]

TL;DR

Keep Swift builds warning-free and make local app launch verification deterministic. This compact replacement preserves the useful build-quality changes from #912 and #938 in three reviewable commits.

What was happening

• SwiftPM builds emitted warnings without failing, allowing new warning debt to accumulate.
• Pure rate-limit reset presentation logic lived inside a SwiftUI view, which made non-UI behavior actor-isolated and harder to test directly.
• The build script requested process termination without waiting, then verified a replacement launch after one fixed sleep.
• Process-name-only checks could mistake an unrelated executable named OpenUsage for the app.
• Debugging docs overstated the isolation provided by the development bundle identifier.

What this changes

• Treats warnings as errors for both the OpenUsage executable and test targets, and resolves the existing warning sites.
• Moves reset timeline/count presentation into a 56-line Foundation model while leaving the SwiftUI view render-only.
• Waits up to five seconds for existing OpenUsage.app processes to exit and polls the exact staged executable for up to five seconds.
• Ignores unrelated same-name processes while still stopping installed and development app bundles.
• Documents the warning policy, bounded lifecycle checks, process scope, and exact settings/credential isolation boundary.

Heads-up

• Supersedes Enforce warning-free Swift builds #912 and Stabilize dev app launch verification #938; those PRs can be closed after this replacement is accepted.
• The presentation extraction has no intended visual or copy change.

Tests

• bash -n script/build_and_run.sh
• Focused reset and login-shell tests: 24 passed
• swift test: 962 XCTest tests passed, 3 expected skips; 3 Swift Testing tests passed
• Same-name regression: with two unrelated OpenUsage processes present, verify launched the exact staged app and build stopped only that app
• ./script/build_and_run.sh verify: release build, staging, Apple Development signing, launch, and exact-process verification passed
• codesign --verify --deep --strict dist/OpenUsage.app
• git diff --check

---

Note

Low Risk
Mostly build hygiene, test refactors, and dev tooling; the presentation extraction is intended to be behavior-neutral for the Codex resets UI.

Overview
SwiftPM now treats warnings as errors for the app and test targets, with small fixes across providers (drop redundant await on synchronous ModelPricingStore.current()), Copilot date formatting (remove nonisolated(unsafe)), snapshot cache, and a concurrency-safe off-main-thread test.

Rate-limit reset popover logic moves from RateLimitResetsDetail into RateLimitResetsPresentation so timeline/count resolution stays testable without SwiftUI; the view only renders.

script/build_and_run.sh waits up to five seconds for prior OpenUsage app processes to exit, matches PIDs by staged bundle path (not name alone), and polls launch for verify. AGENTS.md and docs/debugging.md document the warning policy, lifecycle behavior, and that the dev bundle id isolates preferences while provider credentials stay shared.

^{Reviewed by Cursor Bugbot for commit ceb9b1d. Bugbot is set up for automated code reviews on this repo. Configure here.}