[UI] Drive image replacement transitions by identity

[NachoSoto]

Summary

• perform non-cache SwiftUI image replacement inside an explicit animation transaction
• retain image identity and the opacity transition so placeholder-to-source replacements crossfade reliably
• preserve the existing behavior of skipping animation for cache hits
• add a reusable Bazel package definition for direct local repository overrides

Root cause

The image carried an animated transition, but the observable renderer assignment itself was not performed in an animation transaction. On a physical device the placeholder could therefore snap to the final image even though the image identity changed.

The clear placeholder remains scoped to the empty/loading branch; an always-present clear layer was removed in response to review because it was redundant.

Validation

• Swift 6 iOS Simulator build
• package test action
• swiftlint --config .swiftlint.yml --strict (0 violations across 34 files)
• WatchChess ChessUITournaments tests and app build using the checked-in Bazel repository definition
• controlled cold-cache WatchChess recording and 30 fps frame extraction on iOS 18.6: independent image fades are visible across successive frames while label baselines and cell bounds remain fixed

Recording

ios18-corrected-placeholder-transition.mp4

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-03T19:38:15.775228Z	44f0a4a	Draft marked ready

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[NachoSoto]

Superseded by the simpler WatchChess hybrid approach: the tournament cell remains SwiftUI, but its background now uses the established UIKit AsyncImageView as a layout-neutral UIViewRepresentable. This restores the proven cross-dissolve without adding SwiftUI image lifecycle machinery.