refactor(scraper): Phase 4 — cross-cutting CancellationToken propagation

[jbarden]

Summary

Implements Phase 4 (cross-cutting items 13–14) of docs/astar-dev-wallpaper-scraper/code-review-2026-07-10.v2.md:

• Item 13 — CancellationToken propagation. The repositories already accepted and propagated tokens after Phases 1–2; this closes the remaining gaps:
  • ConfigurationSaver.SaveUpdatedConfigurationAsync now requires a CancellationToken and passes it to CreateDbContextAsync, SingleAsync, and SaveChangesAsync, using the token-aware Try.RunAsync(operation, cancellationToken) overload. All four call sites (PagedScrapeRunner, SearchWorkflow, TopWallpapersWorkflow, SubscriptionsWorkflow) forward their workflow token.
  • DataSeed.SeedTagsToIgnoreAsync / SeedScrapeConfigurationAsync / SeedFileClassificationsAsync accept and propagate a token (SaveChangesAsync, File.ReadAllLinesAsync).
  • DatabaseInitializationService.InitialiseAsync(CancellationToken = default) propagates to CreateDbContextAsync, MigrateAsync, and the seed calls; also switches from sync CreateDbContext() to CreateDbContextAsync.
• Item 14 — per-section configuration update methods: already implemented in Phase 3 (ScrapeConfigurationService.UpdateConnectionStrings / UpdateUserConfiguration / UpdateSearchConfiguration / UpdateScrapeDirectories / UpsertSearchCategories); verified, no change needed.

Out of scope, flagged for follow-up: ScrapeConfigurationViewModel (UI layer; long-lived context, underscore-prefixed fields) and MainWindow.axaml.cs CancellationToken.None in UI event handlers.

Type of change

• Feature
• Bug fix
• Refactor
• CI/CD
• Documentation
• Maintenance

Related issues / links

Closes #736. Follows #735 (Phase 3), #730/#728/#727/#726 (Phase 2), #721 (Phase 1).

How was this tested?

• Unit tests added/updated
• Manual validation
• Not applicable

Failing tests committed first (TDD), then production code. New tests: token-passed-to-factory and cancelled-token behaviour for ConfigurationSaver, DataSeed (all three seed methods), and DatabaseInitializationService.

dotnet clean && dotnet build --no-restore: 0 errors. 8 warnings, all pre-existing on main (NU1903 vulnerable SQLitePCLRaw.lib.e_sqlite3 in spikes/, AVLN3001 Avalonia XAML resources) — none in the changed projects.

dotnet test --no-build: 3,176 total, 0 failed, 1 skipped (pre-existing skip in AStar.Dev.Utilities.Tests.Unit). Scraper unit project: 448 passed, 0 failed (7 new tests).

Impacted areas

apps/desktop/Scraper/AStar.Dev.Wallpaper.Scraper, apps/desktop/Scraper/AStar.Dev.Wallpaper.Scraper.Tests.Unit

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TDD Checklist (required)

• Builds locally
• Tests pass (dotnet test)
• No new analyzer warnings
• Public API changes reviewed
• Documentation updated (if applicable)
• Not applicable

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How to run tests locally

# Restore and run tests
dotnet restore AStar.Dev.slnx
dotnet test --verbosity normal

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Notes for reviewers

• Ensure CI passed for all OS runners where configured.
• SaveUpdatedConfigurationAsync token parameter is required (no default) so future call sites must propagate; InitialiseAsync keeps = default because the app-startup caller has no token source.
• With a cancelled token, Try.RunAsync rethrows OperationCanceledException rather than converting it to a Fail result — this matches the documented behaviour of the token-aware overload.

🤖 Generated with Claude Code

[github-actions]

Test results

3 149 tests   - 20   3 147 ✅  - 21   1m 4s ⏱️ - 1m 12s
   12 suites  -  1       1 💤 ± 0 
   12 files    -  1       1 ❌ + 1 

For more details on these failures, see this check.

Results for commit 91aeee8. ± Comparison against base commit 83beb20.

This pull request removes 27 and adds 7 tests. Note that renamed tests count towards both.

AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_duplicates_exist_for_one_account_they_do_not_appear_in_another_accounts_results
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_files_have_same_name_but_different_sizes_then_not_returned
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_files_have_same_size_but_different_names_then_not_returned
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_files_share_size_and_filename_then_both_are_returned
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_folders_share_size_and_name_they_are_excluded_from_duplicate_detection
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_items_have_null_size_they_are_excluded_from_duplicate_detection
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_no_duplicate_files_exist_then_returns_empty_list
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenSyncedItemRepository_WhenSearchingForDuplicates ‑ when_three_files_share_size_and_name_then_all_three_are_returned
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.Data.GivenTheMigrationDropFileClassificationRulesTable ‑ when_all_migrations_are_applied_then_file_classification_rules_table_does_not_exist
AStar.Dev.OneDrive.Sync.Client.Tests.Integration.FileClassification.GivenFileAutoCategorisor ‑ when_path_contains_documents_token_then_result_is_none
…

AStar.Dev.Wallpaper.Scraper.Tests.Unit.Services.GivenADatabaseInitializationService ‑ when_initialising_with_a_cancellation_token_then_the_token_is_passed_to_the_context_factory
AStar.Dev.Wallpaper.Scraper.Tests.Unit.Services.GivenADatabaseInitializationService ‑ when_initialising_with_a_cancelled_token_then_an_operation_canceled_exception_is_thrown
AStar.Dev.Wallpaper.Scraper.Tests.Unit.Services.GivenDataSeed ‑ when_seeding_file_classifications_with_a_cancelled_token_then_an_operation_canceled_exception_is_thrown
AStar.Dev.Wallpaper.Scraper.Tests.Unit.Services.GivenDataSeed ‑ when_seeding_scrape_configuration_with_a_cancelled_token_then_an_operation_canceled_exception_is_thrown
AStar.Dev.Wallpaper.Scraper.Tests.Unit.Services.GivenDataSeed ‑ when_seeding_tags_to_ignore_with_a_cancelled_token_then_an_operation_canceled_exception_is_thrown
AStar.Dev.Wallpaper.Scraper.Tests.Unit.Support.GivenAConfigurationSaver ‑ when_saving_with_a_cancellation_token_then_the_token_is_passed_to_the_context_factory
AStar.Dev.Wallpaper.Scraper.Tests.Unit.Support.GivenAConfigurationSaver ‑ when_saving_with_a_cancelled_token_then_an_operation_canceled_exception_is_thrown