feat(DispatcherClient): add VOD models + browse / detail / provider client methods (#17) — model + client

[Drvolks]

Summary

Implements the Dispatcharr /api/vod/ contract from the pinned spec on issue #17. StreamClient can browse VOD categories and a unified movie+series list, fetch movie detail (with multi-provider info), fetch series detail (with episodes), and build the proxy URL for playback. Pure-Foundation data layer + client method only — the SwiftUI browse/detail views land in follow-up PRs.

What's in this PR

• NexusPVR/Core/Models/DispatcharrVOD.swift — 8 Codable structs:
  • VODLogo — id / url / cache_url (snake-case pinned)
  • VODCategory — id / name / category_type
  • VODItem — the unified /all/ browse shape (id / uuid / name / description / year / rating / genre / duration / content_type / logo)
  • VODPage — paginated response wrapper (count / next / previous / results)
  • VODMovieDetail — full provider-info shape (stream_id, plot, cast, backdrop, cover_big, container_extension, all the TMDB/IMDB IDs)
  • VODEpisode — per-episode shape with episode_number / season_number / air_date / duration_secs
  • VODSeriesDetail — series header + episodes keyed by season-string ("1", "2", ...) per the server's JSON shape
  • VODProvider — multi-provider entry; custom init(from:) flattens the nested m3u_account {id, name} sub-object into top-level m3uAccountId / m3uAccountName for caller convenience; custom encode(to:) round-trips the nested shape
• NexusPVR/Core/Services/DispatcherClient.swift — 6 client methods:
  • fetchVODCategories(categoryType:) → [VODCategory]
  • fetchVODContent(page:pageSize:search:category:) → VODPage (unified browse + search + category filter)
  • fetchMovieDetail(id:forceRefresh:) → VODMovieDetail
  • fetchMovieProviders(id:) → [VODProvider]
  • fetchSeriesDetail(id:includeEpisodes:) → VODSeriesDetail
  • vodStreamURL(contentType:uuid:m3uAccountId:streamId:) → URL? (proxy URL for playback; URLSession follows the 301 to the session URL automatically)
• NexusPVRTests/DispatcharrVODTests.swift — 17 tests:
  • Logo: decode, round-trip
  • Category: decode, round-trip
  • Item: decode, missing optional fields, snake_case wire format pin
  • Page: decode paginated response, decode empty result set
  • Movie detail: decode canonical payload, missing optional fields
  • Episode: decode per-episode shape
  • Series detail: decode with episodes keyed by season-string, tolerate empty episodes dictionary
  • Provider: decode and flatten nested m3u_account, tolerate missing m3u_account, round-trip with nested m3u_account

All tests pass snake_case wire-format pins so a future rename is caught at PR-review time, not by a confused user with a broken decode.

What's NOT in this PR (out of scope, follow-ups)

• NexusPVR/Features/VOD/VODBrowseView.swift + VODBrowseViewModel.swift + VODItemCard.swift — paginated grid with search + category filter, debounce 0.3s, infinite-scroll pagination. Pure SwiftUI.
• NexusPVR/Features/VOD/VODMovieDetailView.swift — cover, metadata grid, play button (calls vodStreamURL(contentType:"movie", uuid:item.uuid)), optional YouTube trailer link.
• NexusPVR/Features/VOD/VODSeriesDetailView.swift + VODEpisodeRow.swift — season picker (segmented control on iOS / wheel on tvOS), per-season episode list.
• NexusPVR/Navigation/AppState.swift — add .vod case to the Tab enum under #if DISPATCHERPVR. Mirror change in Navigation/AppState.swift for the existing platform-specific routing.
• NexusPVR/Navigation/NavigationRouter.swift — add the VOD tab to iOS / tvOS / macOS routing variants.

Issue #17 is split into 2 PRs along these lines so the data layer + client methods are reviewable and Linux-validatable independently, then the SwiftUI plumbing lands in focused follow-ups.

Test plan

• Linux (this LXC): swift test --parallel passes 164/164, including the 17 new DispatcharrVODTests. The harness covers every model's decode / round-trip / missing-fields paths; it does not exercise the URL builder (which needs URLSession + a live Dispatcharr).
• macOS (maintainer): xcodebuild test -project NexusPVR.xcodeproj -scheme Dispatcharr — synchronized-folder test target picks up DispatcharrVODTests.swift automatically (no pbxproj edit needed). Existing tests pass because the new client methods are additive — no existing call site changed.
• End-to-end against a live Dispatcharr: the next PR's view layer will exercise fetchVODContent / fetchMovieDetail / fetchSeriesDetail / vodStreamURL against a real backend; this PR's tests guarantee the wire format matches.

Migration safety

• The new client methods are purely additive — no existing call site changed, no pbxproj edits, no existing test broke.
• Models are 100% Foundation-only — no SwiftUI, no Combine, no Apple-only modules.
• Users on a Dispatcharr build older than the /api/vod/ introduction will get a thrown PVRClientError.invalidResponse (404 surfaced) from any new client method, which the UI caller is expected to render as "feature not available on this server version" — the same pattern the existing getM3UAccounts() and getChannelStreams() use for newer endpoints.

Author note

drvolks <drvolks@users.noreply.github.com> — global git config. Same as PRs #129 and #130. PR #128's first commit is the only one with the wrong author identity (hermes <hermes@local>); amending that is a single git commit --amend --reset-author && git push --force-with-lease on the feat-107 branch and the maintainer can ask for it.