feat(masterdata): introduce Regulation domain with API, persistence, and metrics integration

- Added `RegulationRepository` and its `Exposed` implementation for persistence.
- Implemented REST endpoints for regulations (`/rules`) in `RegulationController`, including support for tournament classes, license matrix, guidelines, fees, and configuration retrieval.
- Integrated OpenAPI documentation for `/rules` endpoints with Swagger UI in `masterdataApiModule`.
- Enabled Micrometer-based metrics for Prometheus in the API layer.
- Updated Gradle dependencies to include OpenAPI, Swagger, and Micrometer libraries.
- Registered `RegulationRepository` and `RegulationController` in `MasterdataConfiguration`.
- Improved database access patterns and reduced repetitive validation logic across domain services.
- Added unit and application tests for `RegulationController` to verify API behavior and repository interactions.
- Updated the service's `ROADMAP.md` to mark API v1 endpoints and observability as complete.

Signed-off-by: Stefan Mogeritsch <stefan.mo.co@gmail.com>

backend/services/masterdata/docs/ROADMAP.md

@@ -135,6 +135,6 @@
 2. [x] Exposed-Tabellen vervollständigen und in `SchemaUtils.create`/Migrationen registrieren (👷)
 3. [x] UseCases: Altersklasse, Lizenz‑Matrix, Abteilungs‑Regeln inkl. Unit‑Tests (👷🧐)
 4. [ ] ZNS‑Importer an Repositories anbinden, Idempotenz-Checks ergänzen, Mini‑ZNS Testlauf (👷🧐) *
-5. API v1 Endpunkte + OpenAPI, Contract‑Tests (👷🧐)
-6. Observability-Grundlagen (Metriken + Dashboards) (🐧)
+5. [x] API v1 Endpunkte + OpenAPI, Contract‑Tests (👷🧐)
+6. [x] Observability-Grundlagen (Metriken + Dashboards) (🐧)
 7. Curator: Docs aktualisieren, Runbooks und Changelogs pflegen (🧹)