docs(audit): Parquet cold archive shipped, default off (ScadaBridge#42)

Component-AuditLog Retention & Purge describes the archive: directory and
layout, the three files, consistency with the hash chain (SHARED read,
guarded switch, anchor = archived chain end), fail-closed purge, retention
interplay (per-channel overrides are not archived, their tombstones are),
verify/read, and the AuditLog:Archive configuration. alog.md §13.6/§15.2/§16,
CLAUDE.md, HighLevelReqs AL-12, Component-CLI, Component-ManagementService,
docs/components/{CLI,ManagementService}.md and the CLI README drop the
"deferred / 501" wording and document `audit archive list|verify` and the
parquet export.

Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV

docs/components/ManagementService.md

@@ -128,7 +128,7 @@ private void HandleEnvelope(ManagementEnvelope envelope)
 `AuditEndpoints.MapAuditAPI` registers two GET endpoints that go directly to `IAuditLogRepository`, bypassing the actor:
 
 - `GET /api/audit/query` — keyset-paged JSON result. Requires `OperationalAudit` permission (Admin / Audit / AuditReadOnly roles). Accepts `channel`, `kind`, `status`, `sourceSiteId`, `correlationId`, `executionId`, `parentExecutionId`, `fromUtc`, `toUtc`, `pageSize`, and cursor params `afterOccurredAtUtc`/`afterEventId`. Returns `{ events, nextCursor }` where `nextCursor` is explicit `null` on the last page.
-- `GET /api/audit/export` — server-side streaming export (CSV or JSONL) of all matching rows, paging the repository internally at 1 000 rows per batch and flushing after each batch. Requires `AuditExport` permission (Admin / Audit roles). `format=parquet` returns HTTP 501 (deferred).
+- `GET /api/audit/export` — server-side streaming export (CSV, JSONL or Parquet) of all matching rows, paging the repository internally at 1 000 rows per batch and flushing after each batch (Parquet: after each 10 000-row row group; same 24 columns, content type `application/vnd.apache.parquet` — ScadaBridge#42). Requires `AuditExport` permission (Admin / Audit roles).
 
 Both endpoints apply the same HTTP Basic Auth / LDAP / role flow as `/management`. Site-scoped callers have their `sourceSiteId` filter intersected with their `PermittedSiteIds`; an explicit out-of-scope filter returns HTTP 403 rather than silently empty results.