Fix pet record Blood/Allergies display and CloudKit tombstone conflict on delete/set-local

[Copilot]

Blood and Allergies sections were incorrectly shown in the viewer for pet records despite being suppressed in the editor. Both "Set Local" and cloud record deletion silently failed to write CloudKit tombstones due to a save conflict, preventing deletions from propagating to other devices.

Pet record viewer: hide Blood & Allergies

The editor already guards these sections with if record.isPet { EmptyView() }. The viewer (both card TabView and list Form) had no equivalent guard. Added if !record.isPet around Blood and Allergies in both cardPages and viewerFormList.

CloudKit tombstone: fix "record to insert already exists"

createTombstone was constructing a fresh CKRecord(recordType:, recordID:) without a recordChangeTag. CloudKit treats any save without a change tag as an INSERT — rejected when the record already exists in CloudKit.

This silently broke both callers:

• deleteSyncRecord → error thrown and shown to the user
• disableCloud (Set Local) → error caught and logged only; tombstone never written; other devices never saw the deletion

Fix: fetch the existing CKRecord first to obtain its change tag, then apply tombstone fields and save as an UPDATE. Fall back to INSERT only when the record is genuinely absent.

let ckRecord: CKRecord
do {
    ckRecord = try await database.record(for: ckID)  // gets recordChangeTag
} catch {
    if let ck = error as? CKError, ck.code == .unknownItem {
        ckRecord = CKRecord(recordType: medicalRecordType, recordID: ckID)
    } else { throw error }
}
// apply tombstone fields, then save as UPDATE

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[Copilot]

Pull request overview

This PR fixes two distinct issues in the Purus Health app: incorrect display of Blood and Allergies sections for pet records in the viewer, and a CloudKit tombstone creation failure that prevented deletion sync across devices.

Changes:

• Hide Blood and Allergies sections in the record viewer for pet records (both card and list views) to match the editor behavior
• Fix CloudKit tombstone creation by fetching existing records to obtain recordChangeTag before updating, resolving "record to insert already exists" errors

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
PurusHealth/Views/RecordEditorView.swift	Added if !record.isPet guards around Blood and Allergies sections in both cardPages and viewerFormList to hide these human-only sections for pet records
PurusHealth/Services/CloudSyncService.swift	Modified createTombstone to fetch existing CloudKit record first to obtain recordChangeTag, enabling UPDATE operations instead of failing INSERTs