Finalize user-engine contracts and operability

src/user_engine/projections.py

@@ -8,6 +8,14 @@ from user_engine.domain import Actor, ProjectionType
 from user_engine.service import Projection, UserEngineService
 
 
+@dataclass
+class CacheStatus:
+    entries: int
+    tenants: tuple[str, ...]
+    applications: tuple[str, ...]
+    users: tuple[str, ...]
+
+
 @dataclass
 class ClaimsEnrichmentProjectionCache:
     """Cache claims-enrichment projections for external token adapters.
@@ -47,3 +55,11 @@ class ClaimsEnrichmentProjectionCache:
         for key in tuple(self._cache):
             if key[2] == user_id:
                 del self._cache[key]
+
+    def status(self) -> CacheStatus:
+        return CacheStatus(
+            entries=len(self._cache),
+            tenants=tuple(sorted({key[0] for key in self._cache})),
+            applications=tuple(sorted({key[1] for key in self._cache})),
+            users=tuple(sorted({key[2] for key in self._cache})),
+        )