STATE-WP-0062 T5: docs, first-party↔repo test, mark workplan finished

- Add /docs/services reference (two-dimension model, persistence, API) and a
  pointer note from /docs/tpsc; add it to the Reference nav.
- Add a test asserting first_party.repo_slug resolves to a managed_repos FK
  (8 services tests green).
- Mark STATE-WP-0062 tasks done / status finished.

Known classes seeded in the live catalog via the API (Gitea, Postgres as
self-hosted/third-party; State Hub as self-hosted/first-party at Level 2).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

dashboard/src/docs/tpsc.md

@@ -7,6 +7,11 @@ title: Third-Party Services Catalog (TPSC)
 The TPSC tracks external service dependencies (APIs, SaaS, CLIs) across all
 registered repos — complementing the SBOM for package dependencies.
 
+> **Now part of the broader service catalog.** TPSC is the `cloud_hosted` +
+> `third_party` quadrant of the two-dimension [service catalog](/docs/services).
+> Catalog rows have migrated into `service_catalog`; the `/tpsc/*` endpoints and
+> per-repo `tpsc.yaml` dependency snapshots continue to work unchanged.
+
 ---
 
 ## Why TPSC?