refactor(tracker-core): migrate consumers to narrow persistence traits (#1715)

[josecelano]

Summary

Closes #1715 (subissue of #1525 — Overhaul Persistence).

Replaces all Arc<Box<dyn Database>> consumer wiring with the four narrow
traits introduced in #1714: AuthKeyStore, TorrentMetricsStore,
WhitelistStore, and SchemaMigrator.

Changes

New

• DatabaseStores bundle in databases::setup — initialize_database now
  returns this struct instead of Arc<Box<dyn Database>>

Updated consumers

Consumer	Narrow trait
DatabaseKeyRepository	Arc<dyn AuthKeyStore>
DatabaseDownloadsMetricRepository	Arc<dyn TorrentMetricsStore>
WhitelistRepository / whitelist::setup	Arc<dyn WhitelistStore>
TrackerCoreContainer	DatabaseStores fields
Benchmark binary operations	narrow traits per operation
authentication/handler.rs tests	MockAuthKeyStore directly
REST API server force_database_error tests	narrow trait mocks

Cleanup

• Database removed from databases::mod public re-export (now private to
  the driver layer)
• All callers in http-tracker-core, udp-tracker-server, and
  axum-http-tracker-server updated
• Spec file renamed to 1715-1525-04b-migrate-consumers-to-narrow-traits.md
  with cross-references updated in ADR and EPIC plan

Testing

• cargo test --workspace --all-features — all tests pass
• linter all — exit code 0

[codecov]

Codecov Report

❌ Patch coverage is 42.23602% with 372 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.39%. Comparing base (ed0d168) to head (356699b).
⚠️ Report is 10 commits behind head on develop.

Files with missing lines	Patch %	Lines
...ges/tracker-core/src/databases/driver/mysql/mod.rs	7.31%	76 Missing ⚠️
...-core/src/databases/driver/mysql/auth_key_store.rs	0.00%	55 Missing ⚠️
...rc/databases/driver/mysql/torrent_metrics_store.rs	0.00%	51 Missing ⚠️
...core/src/databases/driver/mysql/schema_migrator.rs	0.00%	46 Missing ⚠️
...core/src/databases/driver/mysql/whitelist_store.rs	0.00%	39 Missing ⚠️
...core/src/databases/driver/sqlite/auth_key_store.rs	65.27%	13 Missing and 12 partials ⚠️
...ore/src/databases/driver/sqlite/whitelist_store.rs	54.90%	13 Missing and 10 partials ⚠️
...c/databases/driver/sqlite/torrent_metrics_store.rs	70.31%	6 Missing and 13 partials ⚠️
...es/tracker-core/src/databases/driver/sqlite/mod.rs	75.00%	4 Missing and 7 partials ⚠️
...ore/src/databases/driver/sqlite/schema_migrator.rs	86.27%	0 Missing and 7 partials ⚠️
... and 7 more

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1716      +/-   ##
===========================================
+ Coverage    81.27%   81.39%   +0.12%     
===========================================
  Files          340      348       +8     
  Lines        25034    25017      -17     
  Branches     25034    25017      -17     
===========================================
+ Hits         20346    20363      +17     
+ Misses        4428     4395      -33     
+ Partials       260      259       -1     

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[Copilot]

Pull request overview

Migrates consumer wiring across the workspace from the aggregate Database trait (Arc<Box<dyn Database>>) to the four narrow persistence traits (AuthKeyStore, TorrentMetricsStore, WhitelistStore, SchemaMigrator) by introducing a DatabaseStores bundle returned from initialize_database.

Changes:

• Introduces DatabaseStores in tracker-core and updates initialize_database to return it (with one Arc<dyn ...> per persistence context).
• Refactors repositories/services/tests/benchmarks across tracker-core, HTTP/UDP servers, and axum REST API tests to depend on narrow traits instead of Database.
• Splits SQLite/MySQL driver implementations into per-trait modules and updates docs/spec references + ADR discoverability links.

Reviewed changes

Copilot reviewed 51 out of 51 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
packages/udp-tracker-server/src/handlers/mod.rs	Updates tests to pass torrent_metrics_store instead of full Database.
packages/udp-tracker-server/src/handlers/announce.rs	Updates tests to pass torrent_metrics_store instead of full Database.
packages/tracker-core/src/whitelist/test_helpers.rs	Wires whitelist helpers via DatabaseStores.whitelist_store.
packages/tracker-core/src/whitelist/setup.rs	Narrows dependency from Database to WhitelistStore.
packages/tracker-core/src/whitelist/repository/persisted.rs	Updates persisted whitelist repository to store Arc<dyn WhitelistStore>.
packages/tracker-core/src/whitelist/manager.rs	Updates whitelist manager tests to use DatabaseStores.whitelist_store.
packages/tracker-core/src/torrent/manager.rs	Updates torrent manager tests to use DatabaseStores.torrent_metrics_store.
packages/tracker-core/src/test_helpers.rs	Updates handler test wiring to use DatabaseStores.torrent_metrics_store.
packages/tracker-core/src/statistics/persisted/downloads.rs	Narrows downloads metrics repository to TorrentMetricsStore.
packages/tracker-core/src/databases/traits/torrent_metrics.rs	Adds ADR-linked rationale note for TorrentMetricsStore scope.
packages/tracker-core/src/databases/traits/mod.rs	Adds ADR link in module-level docs.
packages/tracker-core/src/databases/setup.rs	Introduces DatabaseStores + returns it from initialize_database.
packages/tracker-core/src/databases/mod.rs	Stops publicly re-exporting the aggregate Database trait.
packages/tracker-core/src/databases/driver/sqlite/whitelist_store.rs	New SQLite WhitelistStore impl module.
packages/tracker-core/src/databases/driver/sqlite/torrent_metrics_store.rs	New SQLite TorrentMetricsStore impl module.
packages/tracker-core/src/databases/driver/sqlite/schema_migrator.rs	New SQLite SchemaMigrator impl module.
packages/tracker-core/src/databases/driver/sqlite/mod.rs	New SQLite driver module root after split.
packages/tracker-core/src/databases/driver/sqlite/auth_key_store.rs	New SQLite AuthKeyStore impl module.
packages/tracker-core/src/databases/driver/sqlite.rs	Removes old monolithic SQLite driver file in favor of split modules.
packages/tracker-core/src/databases/driver/mysql/whitelist_store.rs	New MySQL WhitelistStore impl module.
packages/tracker-core/src/databases/driver/mysql/torrent_metrics_store.rs	New MySQL TorrentMetricsStore impl module.
packages/tracker-core/src/databases/driver/mysql/schema_migrator.rs	New MySQL SchemaMigrator impl module.
packages/tracker-core/src/databases/driver/mysql/mod.rs	New MySQL driver module root after split.
packages/tracker-core/src/databases/driver/mysql/auth_key_store.rs	New MySQL AuthKeyStore impl module.
packages/tracker-core/src/databases/driver/mysql.rs	Removes old monolithic MySQL driver file in favor of split modules.
packages/tracker-core/src/databases/driver/mod.rs	Removes driver factory build and narrows visibility of metric constant.
packages/tracker-core/src/container.rs	Refactors TrackerCoreContainer to hold DatabaseStores and wire narrow traits.
packages/tracker-core/src/bin/persistence_benchmark/driver_bench/operations/whitelist.rs	Narrows benchmark operation to WhitelistStore.
packages/tracker-core/src/bin/persistence_benchmark/driver_bench/operations/torrent.rs	Narrows benchmark operation to TorrentMetricsStore.
packages/tracker-core/src/bin/persistence_benchmark/driver_bench/operations/mod.rs	Narrows benchmark operation signatures to the relevant traits.
packages/tracker-core/src/bin/persistence_benchmark/driver_bench/operations/keys.rs	Narrows benchmark operation to AuthKeyStore.
packages/tracker-core/src/bin/persistence_benchmark/driver_bench/mod.rs	Updates benchmark wiring to pass the correct store fields.
packages/tracker-core/src/bin/persistence_benchmark/driver_bench/database/mod.rs	Stores DatabaseStores and uses SchemaMigrator for reset logic.
packages/tracker-core/src/authentication/mod.rs	Updates auth tests to pass auth_key_store.
packages/tracker-core/src/authentication/key/repository/persisted.rs	Narrows persisted key repository to AuthKeyStore.
packages/tracker-core/src/authentication/handler.rs	Refactors handler tests to use MockAuthKeyStore directly.
packages/http-tracker-core/src/services/scrape.rs	Updates tests to use torrent_metrics_store.
packages/http-tracker-core/src/services/announce.rs	Updates tests to use torrent_metrics_store.
packages/http-tracker-core/benches/helpers/util.rs	Updates benchmark helper wiring to use torrent_metrics_store.
packages/axum-rest-tracker-api-server/tests/server/v1/contract/context/whitelist.rs	Updates failure-injection to operate via schema_migrator.
packages/axum-rest-tracker-api-server/tests/server/v1/contract/context/auth_key.rs	Updates failure-injection to operate via schema_migrator.
packages/axum-rest-tracker-api-server/tests/server/mod.rs	Changes force_database_error to accept Arc<dyn SchemaMigrator>.
packages/axum-http-tracker-server/src/v1/handlers/announce.rs	Updates tests to use torrent_metrics_store.
docs/packages.md	Adds “Design Decisions” section linking to ADR; reflows tables.
docs/issues/1715-1525-04b-migrate-consumers-to-narrow-traits.md	Updates references to include the GitHub issue number.
docs/issues/1525-overhaul-persistence.md	Updates spec filename reference for subissue 04b.
docs/adrs/20260429000000_keep_database_as_aggregate_supertrait.md	Updates spec links + adds revisit criteria section.
.github/skills/dev/planning/create-adr/SKILL.md	Documents ADR/code cross-linking convention.
.github/skills/dev/github/link-subissue-to-parent-issue/SKILL.md	Adds a new skill doc for linking sub-issues via GitHub API.
.github/agents/implementer.agent.md	Codifies ADR discoverability convention.
.github/agents/github-operator.agent.md	Adds a GitHub-operator agent doc for workflow operations.

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[josecelano]

ACK 356699b