ios metadata pull and push: App Store listing in the fastlane deliver layout

[Interlap01]

What

builder ios metadata pull and builder ios metadata push sync the App Store listing with files, from any platform, on the existing ASC client.

• Fields: per-locale description, keywords, What's New (release_notes), promotional text, marketing/support URL (appStoreVersionLocalizations); name, subtitle, privacy URL (appInfoLocalizations); primary/secondary category (appInfos relationships); screenshots per display type (appScreenshotSets / appScreenshots).
• Layout is fastlane deliver's: metadata/<locale>/<field>.txt, metadata/{primary,secondary}_category.txt, screenshots/<locale>/. Each screenshot's display type comes from its pixel size, or from a <DISPLAY_TYPE>/ subfolder (mapping table in the README). --metadata-dir and --screenshots-dir set the directories.
• Version: the editable one by default. --version X.Y picks a version, and push creates it if it doesn't exist, then re-plans against the localizations App Store Connect copied into it. The app is found with resolveApp (--bundle-id, --ipa, ios.bundleId, newest dist IPA).
• push: checks lengths (name/subtitle 30, keywords 100, promo 170, description/notes 4000), URLs, categories, screenshot sizes and the 10-per-set limit locally before any request. Then it prints one Will ... line per difference and needs --yes (--dry-run only prints). Screenshots are compared by MD5 and only pushed with --screenshots. By default missing ones are appended; --replace-screenshots deletes and re-uploads a set that differs. Upload: reserve, PUT the upload operations, PATCH uploaded with sourceFileChecksum, poll assetDeliveryState.
• pull: writes non-empty fields and never deletes local files unless --clean. Screenshots download only with --screenshots. A pulled tree pushes back as an empty plan.
• --json on both, like the other asc commands. Exposed as pkg/metadata, plus aliases in pkg/asc.

Why

Roadmap item 12: manage store metadata without a Mac, a browser or fastlane, and let existing fastlane users migrate in place.

How tested

• internal/asc: screenshot reserve/upload/commit/poll flow, failed delivery, image URL template, localization and category requests (null secondary category).
• internal/metadata: tested against a stateful fake ASC server. Covers local validation with no requests made, the diff/plan text and the minimal PATCH bodies, creating a new locale (and requiring name.txt for it), creating a version and re-planning, refusing a locked version, screenshot upload/append/replace and the set limit, pixel-size inference, and pull with and without --clean/--screenshots plus the round trip.
• cmd/builder: pull → edit → push without --yes / --dry-run --json / --yes, and local validation failing before any write.
• go test -race ./..., golangci-lint v2.12.2 (CI version): 0 issues. No live App Store Connect calls.

Left out

Copyright, review information, age rating, subcategories, app previews (video), reordering screenshots within a set, and fastlane's default/ locale fallback.