fix(record-store): ensure record sync before marking as stored

[dirvine]

Record Store Sync Improvements

Problem

The can_store_after_restart test was failing because records were not being properly synced to disk before being marked as stored. This could lead to potential data loss in case of system crashes or unexpected restarts.

Solution

• Added proper file sync operation after writing record to disk using sync_all()
• Combined file write and sync operations into a single Result chain using and_then
• Improved error handling for both write and sync operations
• Only send AddLocalRecordAsStored command after both operations succeed

Testing

• All tests now pass, including the previously failing can_store_after_restart test
• Added proper error handling and logging for write/sync failures
• Verified that records are properly persisted after system restarts

Impact

This change improves data reliability by ensuring that records are properly synced to disk before being marked as stored. This prevents potential data loss in scenarios where the system crashes or restarts unexpectedly after a write but before the data is fully synced to disk.

[grumbach]

LGTM