feat: add asynchronous schema tracking export with ZIP segments and job status API

[devlead]

Introduce end-to-end export of change-tracking data for a configured sync table: full rows for inserts/updates and primary keys for deletes, written as streamed JSON-in-ZIP to blob storage with Azure Table coordination and queue-based orchestration.

HTTP (Function auth):

• POST .../schema/tracking/{tableId}/export with author, referenceId, purpose; persists blobs and exportjobs row, returns 202 with Location to status.
• GET .../export/status/{*correlationId} for job detail (optional result SAS when result.json exists) or list when correlation segment is empty.

Workers and storage:

• Queues: exportjob dispatch; exportjob-{updated,inserted,deleted} segments; matching -done completion queues and -error dead-letter style correlation messages on segment failure.
• Blobs: export container (request.json, job.json, response/*.zip, result.json).
• Tables: exportjobs partition area_jobId_tableId (sanitized), row key v7 GUID.

Implementation:

• SchemaTrackingExportService for create, list, status, dispatch, segment processing, optimistic ETag merges, finalize with 7-day read SAS URIs.
• SchemaTrackingExportStreamingZip streams SqlDataReader into one ZIP entry.
• SqlStatementExtensions: CHANGETABLE segment SELECTs; Guid.CreateVersion7 for new identifiers where applicable.

Also: README schema tracking export section; Azure.Data.Tables dependency; Directory.Packages.props bumps (Functions worker, OpenTelemetry, SqlClient, Cronos, etc.).