feat(auth): swap stub for PrismaScopeResolver + add test-tenant seed (ADR-0026 PR 2a)

PrismaScopeResolver replaces StubScopeResolver in AuthModule. Queries
user_scopes WHERE userId AND (expiresAt IS NULL OR expiresAt > NOW())
and maps each row to a typed Scope via a pure toScope helper.
Defensive: off-catalogue kinds are skipped + warn-logged rather than
thrown (write path is the canonical guard via the drift gate).

prisma/seed.ts populates Person + User + UserScope rows for the 19
test-tenant personas per notes/test-tenant-role-assignments.md. The
persona matrix (slug + email + displayName + scope tuples) is
hardcoded in the seed; tenant-private Entra oids are read from
TEST_TENANT_PERSONAS_PATH (default infra/test-tenant.personas.json,
gitignored). Idempotent on every level: User unique on entraOid,
UserScope unique on (userId, kind, value).

StubScopeResolver class stays exported from scope-resolver.ts for
spec fixtures + as a future force-everyone-unrestricted dev hint,
but is no longer wired by default.

The admin /admin/users/:id/scopes screen is split into the follow-up
PR 2b - the Angular SPA work is a different mode from this backend +
data PR.

Local: drift gate 4/24/7/3 clean, 29 drift-gate specs pass, portal-bff
lint 0 errors, 774 portal-bff specs pass (+8 for the resolver spec).

package.json

@@ -57,7 +57,8 @@
     }
   },
   "prisma": {
-    "schema": "apps/portal-bff/prisma/schema.prisma"
+    "schema": "apps/portal-bff/prisma/schema.prisma",
+    "seed": "ts-node --transpile-only --compiler-options {\"module\":\"CommonJS\",\"esModuleInterop\":true,\"target\":\"ES2020\"} apps/portal-bff/prisma/seed.ts"
   },
   "devDependencies": {
     "@analogjs/vite-plugin-angular": "~2.5.0",