feat(httpapi): add local audit log with portal dual-write

Локальный audit_log (миграции pg/sqlite), GET /v1/audit, запись на CRUD и async push в auth-portal (source_app=bgp).

Co-authored-by: Cursor <cursoragent@cursor.com>

cmd/evobgp-api/main.go

@@ -37,6 +37,7 @@ func main() {
 		AuthPortalURL:      firstNonEmpty(os.Getenv("EVOBGP_AUTH_PORTAL_URL"), os.Getenv("AUTH_PORTAL_URL")),
 		PortalTenantID:     strings.TrimSpace(os.Getenv("EVOBGP_PORTAL_TENANT_ID")),
 		AuthRequired:       boolFromEnv("EVOBGP_AUTH_REQUIRED", "AUTH_REQUIRED"),
+		AuditIngestSecret:  firstNonEmpty(os.Getenv("EVOBGP_AUTH_AUDIT_INGEST_SECRET"), os.Getenv("AUTH_AUDIT_INGEST_SECRET")),
 	}
 	srv, err := httpapi.New(opts)
 	if err != nil {