favorites and image details model tests

[chizberg]

Two more model test suites.

FavoritesModelTests — pins that favorites dedup keys off cid alone rather than the whole struct (Model.Image.== compares only cid):

• re-adding a photo with an existing cid is a no-op: the first entry is kept and the storage effect is not re-invoked;
• removal finds the stored entry by cid even when every other field of the passed instance differs (e.g. one rehydrated from Storage.Image); an unknown cid touches neither state nor storage.

ImageDetailsModelTests — description-link routing, which hinges on a branchy URL parse (host + /p/ + integer cid):

• a link to a pastvu photo loads it from the remote and presents a nested details screen; loadingAnotherImage is set synchronously and cleared once the nested model is presented;
• an external link is handed to the browser;
• a pastvu link that is not a photo page (e.g. a user profile) also goes to the browser instead of being mistaken for a photo.

Rebased onto fresh origin/main. Locally: xcodebuild test — TEST SUCCEEDED; swiftlint --strict and swiftformat . --lint — clean.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds two new test suites to pin important model behaviors: favorites deduplication keyed by Model.Image.cid, and URL routing from the Image Details description links (recursive navigation for pastvu.com/p/<cid> vs. opening everything else in the browser).

Changes:

• Introduces FavoritesModelTests covering add/remove deduplication semantics by cid (including no-op persistence behavior).
• Introduces ImageDetailsModelTests covering link routing for PastVu photo links vs. external/non-photo PastVu links.
• Adds local async polling helper (eventually) in the new Image Details tests to observe async reducer effects.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
RewindTests/FavoritesModelTests.swift	New tests that lock in favorites add/remove semantics and persistence no-ops when deduping by cid.
RewindTests/ImageDetailsModelTests.swift	New tests that lock in description-link routing behavior for PastVu photo links vs. browser hand-off.

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[chizberg]

🤖 Written by Claude Code (AI agent), posted from @chizberg's account.

Checked this — it's a false positive; the closure body does run on the main actor.

Remote.impl is declared as (Args) async throws -> Response (Rewind/Utils/Remote.swift:11), without @Sendable. A non-@Sendable closure literal formed inside an isolated context inherits that isolation, and Harness.makeModel() is @MainActor-isolated. So the closure is @MainActor, and await impl(args) from the reducer's Task hops back to the main actor before entering the body.

Two checks:

1. Runtime. Temporarily put MainActor.assertIsolated() as the first line of the closure body and ran the target in Debug (where assertIsolated is live): TEST SUCCEEDED, no trap. The closure definitely executes — pastvuPhotoLinkOpensNestedDetails asserts requestedCids == [linkedCid].

2. Compiler. Forced a clean recompile of the test files: zero isolation/Sendable diagnostics for ImageDetailsModelTests.swift. Meanwhile the already-merged MapModelTests.swift, which writes await self.record(params) in the exact same position, gets three no 'async' operations occur within 'await' expression warnings (lines 370, 371, 379) — the compiler considers those awaits redundant precisely because that closure is likewise main-actor-isolated.

One caveat worth noting: this rests on isolation inheritance under Swift 5 language mode (SWIFT_VERSION = 5.0). Under Swift 6, converting a @MainActor closure to a non-isolated function type would be diagnosed — but that would affect MapModelTests and production call sites equally, so it's a project-wide migration question rather than something specific to this PR.

Added a comment at the harness so this isn't re-derived next time (06fb802).