Merge #2171: docs(issues): publish SI-4 torrent cleanup specification

1cacd68 docs(review): document PR #2171 Copilot suggestions audit (Jose Celano)
26d706d docs(issues): clarify torrent cleanup specification (Jose Celano)
1440af2 docs(issues): publish SI-4 torrent cleanup specification (Jose Celano)

Pull request description:

  ## Summary

  Publishes the approved specification for #2169, SI-4 in the #1488 shutdown roadmap.

  - Replaces the outdated pre-spawned `JoinHandle` proposal with an unspawned, token-aware cleanup runner directly owned by `JobManager::spawn`.
  - Defines explicit normal outcomes for cancellation and weak-manager expiry.
  - Requires deterministic lifecycle and named-supervisor-outcome tests.
  - Adds direct-binary SIGTERM verification and a functional inactive-peer cleanup scenario through the REST API.
  - Requires a separately committed reusable manual cleanup verification skill after the manual scenario establishes the exact procedure.

  Related to #2169

  ## Validation

  - `linter all`
  - `git diff --check`
  - Mandatory pre-commit checks
  - Pre-push checks: nightly format and workspace checks, documentation build, and full test suite

ACKs for top commit:
  josecelano:
    ACK 1cacd68

Tree-SHA512: 99b08b20a5e9d700502d212a44cd3a93135e9f5de6586ba71f0fe04560949884877cfd150ffa81a76452ac445490b04300a31c2ce78aadc3e36b895c79b8d630

Author: josecelano

docs/copilot-pr-reviews/pr-2171-copilot-suggestions.md

@@ -0,0 +1,39 @@
+---
+semantic-links:
+  skill-links:
+    - process-copilot-suggestions
+  related-artifacts:
+    - .github/skills/dev/pr-reviews/process-copilot-suggestions/SKILL.md
+---
+
+<!-- cspell:disable -->
+
+<!-- skill-link: process-copilot-suggestions -->
+
+# PR #2171 Copilot Suggestions Tracking
+
+Source: Copilot PR review threads for <https://github.com/torrust/torrust-tracker/pull/2171>
+
+Status legend:
+
+- `action`: code/docs change applied
+- `no-action`: suggestion reviewed; no code change needed
+- `resolved`: thread resolved in PR
+
+## Processing Log
+
+- 2026-09-08: Started processing suggestions.
+- 2026-09-08: Corrected all three reviewed specification gaps, replied to each Copilot thread, and resolved each thread.
+
+## Suggestions
+
+| #   | Thread ID               | Path                                                               | URL                                                                           | Suggestion Summary                                                      | Decision                                                                                          | Reply URL                                                                     | Status | Thread State |
+| --- | ----------------------- | ------------------------------------------------------------------ | ----------------------------------------------------------------------------- | ----------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------- | ------ | ------------ |
+| 1   | `PRRT_kwDOGp2yqc6gOpZd` | `docs/issues/open/2169-1488-si-4-migrate-torrent-cleanup/ISSUE.md` | <https://github.com/torrust/torrust-tracker/pull/2171#discussion_r3957681415> | Use owned inputs for the `'static` direct-component runner.             | action — changed `Core` and `Arc<TorrentsManager>` parameters to owned values.                    | <https://github.com/torrust/torrust-tracker/pull/2171#discussion_r3957927345> | DONE   | RESOLVED     |
+| 2   | `PRRT_kwDOGp2yqc6gOpaB` | `docs/issues/open/2169-1488-si-4-migrate-torrent-cleanup/ISSUE.md` | <https://github.com/torrust/torrust-tracker/pull/2171#discussion_r3957681465> | Do not reference the planned manual verification skill as if it exists. | action — removed the premature related-artifact reference; T6 remains the planned creation point. | <https://github.com/torrust/torrust-tracker/pull/2171#discussion_r3957934424> | DONE   | RESOLVED     |
+| 3   | `PRRT_kwDOGp2yqc6gOpaR` | `docs/issues/open/2169-1488-si-4-migrate-torrent-cleanup/ISSUE.md` | <https://github.com/torrust/torrust-tracker/pull/2171#discussion_r3957681488> | Name the deterministic application wiring/outcome test and command.     | action — added planned test names, exact invocations, and required assertions.                    | <https://github.com/torrust/torrust-tracker/pull/2171#discussion_r3958000099> | DONE   | RESOLVED     |
+
+## Notes
+
+- Keep this file as an audit log of review handling for the PR.
+- Reply on every PR suggestion thread before resolving it so the decision is visible to reviewers.

docs/issues/drafts/1488-si-4-migrate-torrent-cleanup/ISSUE.md

@@ -152,7 +152,7 @@ deterministic tests, and manual evidence.
 | 0        | #1588 | [Revalidate task inventory](../1588-review-shutdown-process-for-all-tasks-jobs/ISSUE.md)                                  | Open       | Implementation-time inventory and ownership evidence; no runtime behavior changes.                   |
 | 1        | SI-1  | [Add `SIGTERM` at `main()`](../2132-add-sigterm-to-main/ISSUE.md)                                                         | Open #2132 | Incremental signal-boundary compatibility fix.                                                       |
 | 2        | #1586 | [Evaluate `JoinSet` for `JobManager`](../1586-evaluate-job-manager-join-set/ISSUE.md)                                     | Open       | Direct supervisor task ownership, concurrent outcomes, and explicit escalation policy.               |
-| 3        | SI-4  | [Migrate torrent cleanup](../../drafts/1488-si-4-migrate-torrent-cleanup/ISSUE.md)                                        | Draft      | One periodic component adopts token cancellation.                                                    |
+| 3        | SI-4  | [Migrate torrent cleanup](../2169-1488-si-4-migrate-torrent-cleanup/ISSUE.md)                                              | Open #2169 | One periodic component adopts token cancellation.                                                    |
 | 4        | SI-5  | [Migrate activity metrics](../../drafts/1488-si-5-migrate-activity-metrics-updater/ISSUE.md)                              | Draft      | One periodic component adopts token cancellation.                                                    |
 | 5        | SI-2  | [Add token-aware server lifecycle API](../../drafts/1488-si-2-remove-global-shutdown-signal/ISSUE.md)                     | Draft      | Additive `torrust-server-lib` API; retain legacy shutdown compatibility.                             |
 | 6        | SI-10 | [Add token-aware, joinable Axum drain helper](../../drafts/1488-si-10-add-token-aware-axum-drain-helper/ISSUE.md)         | Draft      | Additive helper alongside existing API; no consumer breaks.                                          |