Harden downloads and offline playback

[zachyzissou]

Problem

Downloads/offline playback need a reliability pass so interrupted downloads, cleanup, storage state, and offline playback are dependable.

Acceptance criteria

• Reconcile interrupted downloads on launch and after network loss.
• Verify downloaded episodes play offline and respect playback position/rate.
• Add cleanup and retry UX for failed downloads.
• Surface storage/download state clearly in Library, Episode Detail, and Player.
• Preserve existing download service tests and add missing edge coverage.

Agent execution contract

Readiness: agent:needs-spec
Lane: Downloads/offline

Start in these files:

• OffScript/DownloadService.swift
• OffScript/DownloadButton.swift
• OffScript/EpisodeDetailView.swift
• OffScript/PlayerView.swift
• OffScriptTests/OffScriptTests.swift

Required verification:

• xcodebuild test -project OffScript.xcodeproj -scheme OffScript -destination 'platform=iOS Simulator,OS=latest,name=iPhone 17 Pro' -only-testing:OffScriptTests CODE_SIGNING_ALLOWED=NO
• Offline playback/manual file-state checklist for touched paths.

Non-goals / guardrails:

• Do not delete user files without explicit state/retry UI.
• Do not claim offline playback fixed without offline smoke.

PR expectation: Needs narrowed edge-case spec before low-thinking implementation.

Low-thinking agents must follow docs/AGENT_EXECUTION_RUNBOOK.md. If the touched code falls outside the files above, stop and tighten the issue or ask for senior review before continuing.

[zachyzissou]

Status: parked, needs scope cut

This is currently labeled or implied as ready for low-thinking work, but the acceptance criteria are list-of-features rather than a single shippable slice. To unblock:

• Pick one specific feature/failure mode from the candidate list.
• Define what "done" looks like for that one slice (UI test? unit test? real-device pass?).

Until then this can't be picked up autonomously without guessing what to build. Suggest moving to a "Needs Spec" status until a slice is named.

Discovered while reviewing the kanban post-session 2026-04-30.