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

internal/keycloak Adapter (HTTPAdapter + Mock). POST /v1/tenants now provisions a KC organization + IT_ADMIN invite when admin_email is set; KC failures emit keycloak.provision_failed but don't roll back. POST /v1/internal/keycloak/claims resolves the current claim bundle for any (tenant_id|tenant_slug|user_attrs.*) lookup. Mock used in tests + when KEYCLOAK_ADMIN_URL is empty. HTTPAdapter tested against an in-process stub KC (httptest.Server).

Refs: M4.3

internal/config/config.go

@@ -3,6 +3,7 @@ package config
 import (
 	"fmt"
 	"os"
+	"time"
 )
 
 type Config struct {
@@ -10,6 +11,15 @@ type Config struct {
 	Addr           string // listen address, e.g. ":8090"
 	KeycloakIssuer string // e.g. http://localhost:8080/realms/breakpilot-dev
 	DatabaseURL    string // postgres DSN (unused in skeleton; in-memory store)
+
+	// Keycloak Admin API — only used if KeycloakAdminURL is set. Empty
+	// values disable the adapter and tenant-registry falls back to the
+	// Mock (dev convenience).
+	KeycloakAdminURL     string
+	KeycloakRealm        string
+	KeycloakClientID     string
+	KeycloakClientSecret string
+	KeycloakTimeout      time.Duration
 }
 
 func Load() (*Config, error) {
@@ -23,6 +33,12 @@ func Load() (*Config, error) {
 		Addr:           getenv("ADDR", ":8090"),
 		KeycloakIssuer: getenv("KEYCLOAK_ISSUER", "http://localhost:8080/realms/breakpilot-dev"),
 		DatabaseURL:    os.Getenv("DATABASE_URL"),
+
+		KeycloakAdminURL:     os.Getenv("KEYCLOAK_ADMIN_URL"),
+		KeycloakRealm:        getenv("KEYCLOAK_REALM", "breakpilot-dev"),
+		KeycloakClientID:     os.Getenv("KEYCLOAK_CLIENT_ID"),
+		KeycloakClientSecret: os.Getenv("KEYCLOAK_CLIENT_SECRET"),
+		KeycloakTimeout:      10 * time.Second,
 	}, nil
 }