[Foundation/Feature] Pokémon Evolution Dex — scaffold, domain models & parallel family loading

[SongMY01]

What problem does this solve?

Builds a SwiftUI Pokédex on the PokeAPI for the Swift Concurrency Lab.
Shows how async/await, TaskGroup, and @MainActor behave in a real app by loading 50 evolution families + every stage's detail (~150 requests) in parallel — sequentially ~45s, in parallel ~0.6s.

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Approach

ContentView ──→ PokemonViewModel ──→ «protocol» PokemonService
   (View)         (@MainActor)              ▲ implements
                                     PokemonServiceImpl ──→ PokeAPI

• Models — Pokemon, PokemonFamily (one evolution chain per card)
• Service — protocol PokemonService: Sendable (async/throws). PokemonServiceImpl decodes JSON via private DTOs — external shape never leaks past the boundary. ViewModel depends only on the protocol → mock injectable for Testing Lab later.
• ViewModel — @MainActor, orchestrates concurrency with nested TaskGroups
• View — card UI tinted by primary type, per-type colors, Pretendard variable font

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Concurrency Core

Outer TaskGroup ─ 50 families concurrently
   └ Each family: fetchEvolutionChain (must run first — data dependency)
        └ Inner TaskGroup ─ that family's stages concurrently (fetchDetail × N)

• Across families: concurrent · within a family: chain-then-details (dependency)
• Ordering: results arrive scrambled → collected into [id: Pokemon], then speciesIDs.compactMap { byID[$0] } restores evolution order
• Safety: @MainActor keeps @Published updates on main; Sendable lets the service cross task boundaries; loadFamily is static + arg-passed so it never captures the MainActor self

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Diagram

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Review Focus

• Is the nested TaskGroup shape right, or would a flatter structure read more clearly?
• Error handling: any task failure currently resets families = [] — should partial results survive instead?
• Are the Pokemon / PokemonFamily field shapes right for the UI?
• Is the PokemonService boundary (async / throws / Sendable) the right contract?

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Out of Scope / Follow-up

• Swift Testing suite (mock PokemonService, success/failure/timeout/cancellation)