feat(keycloak): M4.3 — Admin API adapter + claim resolver

internal/keycloak/ — Adapter interface with two implementations:
  HTTPAdapter  pgxpool-style real Admin API client with cached client-
               credentials token (auto-refresh, 401 retry).
  Mock         in-process map for unit tests + dev convenience when
               KEYCLOAK_ADMIN_URL is empty. Used by the eachStore harness.

Adapter contract (adapter.go):
  CreateOrgAndInvite(ctx, InviteInput) (*InviteResult, error)
    Creates a KC organization, an IT_ADMIN user, adds the user as a
    member, triggers VERIFY_EMAIL + UPDATE_PASSWORD execute-actions
    email. Atomic from the caller's PoV; partial failures surface as
    typed errors (ErrOrgConflict, ErrUserConflict, ErrUnauthorized,
    ErrUnavailable).
  SyncClaims(ctx, userID, Claims) error
    Pushes tenant_id / tenant_slug / org_roles / products / plan /
    tenant_status into the user's KC attributes — the same shape the
    realm's protocol mappers project into JWTs.
  Health(ctx) error
    Pings /admin/serverinfo; wired into readyz.

Wiring:
  POST /v1/tenants now accepts admin_email + admin_name. When set, the
  adapter creates the org and invites the user. Response wraps the
  tenant with the new TenantCreated{tenant, invite_url} shape so dev
  testers can use the action-token URL without waiting for the email.
  KC failures DO NOT roll the tenant back — they emit a
  keycloak.provision_failed audit event so the operator can resend.
  Successful invites emit keycloak.invite_sent.

  POST /v1/internal/keycloak/claims resolves a tenant's current claim
  bundle. Lookup chain: body.tenant_id → body.tenant_slug →
  body.user_attrs.tenant_id → body.user_attrs.tenant_slug. The realm's
  protocol mapper calls this at token issuance, or operators on demand.

Config: KEYCLOAK_ADMIN_URL / REALM / CLIENT_ID / CLIENT_SECRET; empty
URL falls back to Mock for dev.

OpenAPI: TenantCreated + Claims schemas added; /v1/internal/keycloak/claims
documented. Contract test extended to cover the new endpoint.

Tests:
  internal/keycloak/mock_test.go    Mock semantics: conflict surfacing,
                                    FailNext hook, SyncClaims persistence.
  internal/server/keycloak_test.go  KC provisioning end-to-end via
                                    eachStore: invite_url returned,
                                    mock records, invite_sent audit;
                                    failure path emits provision_failed
                                    but tenant still lands; claims
                                    endpoint resolves via tenant_id /
                                    tenant_slug / user_attrs / 404 / 400.

The real-KC integration test (against a testcontainers-spun KC 26)
lands in a follow-up — gating it behind KEYCLOAK_INTEGRATION=1 + a
slower nightly CI is cleaner than baking 30s+ of KC boot into every PR.

Refs: M4.3

.env.example

@@ -9,3 +9,11 @@ KEYCLOAK_ISSUER=http://localhost:8080/realms/breakpilot-dev
 # only; data lost on restart). Set to use the dev-stack Postgres + run
 # `make migrate-up` first.
 # DATABASE_URL=postgres://platform:platform-dev-pass@localhost:5432/platform?sslmode=disable
+
+# Keycloak Admin API — when these are set, tenant-registry calls the real KC
+# Admin API to provision orgs + invite IT_ADMINs on POST /v1/tenants. Leave
+# empty to use the in-process Mock adapter (no real KC writes).
+# KEYCLOAK_ADMIN_URL=http://localhost:8080
+# KEYCLOAK_REALM=breakpilot-dev
+# KEYCLOAK_CLIENT_ID=tenant-registry-admin
+# KEYCLOAK_CLIENT_SECRET=...from infisical...