Feature: Add custom CloudKit zone support for queries

[leogdion]

Description

The queryRecords() method currently hard-codes the zone name to _defaultZone, which prevents querying custom CloudKit zones.

Current Behavior

// Sources/MistKit/Service/CloudKitService+Operations.swift:105
zoneID: .init(zoneName: "_defaultZone"),

Proposed Solution

Add optional zoneName parameter with default value:

public func queryRecords(
  recordType: String,
  filters: [QueryFilter]? = nil,
  sortBy: [QuerySort]? = nil,
  limit: Int = 100,
  zoneName: String = "_defaultZone"
) async throws(CloudKitError) -> [RecordInfo] {
  // Use provided zoneName instead of hard-coded value
}

Use Cases

• Querying custom zones for advanced CloudKit usage
• Working with shared zones
• Multi-zone applications

References

• Identified in PR Adding Celestra to Demos #134 review by Claude Code (CloudKitService+Operations.swift:105)
• CloudKit Web Services supports custom zones

Priority

Medium - Required for advanced CloudKit features

[leogdion]

This has been implemented. Custom CloudKit zone support is available:

• Sources/MistKit/Service/ZoneID.swift - Zone identifier type
• Zone support integrated throughout the service layer
• CloudKitService.listZones() - List available zones
• Query and modify operations support zone specification

Custom zones can be used for organizing records and enabling features like atomic commits and change tracking.

Closing as completed.