fix: add PITR constraints - standard GPv2, hot/cool only, no HNS

Point-in-time restore only works for:
- Standard GPv2 accounts (not premium)
- Block blobs in hot/cool tier (not cold/archive)
- Not supported on HNS-enabled (Data Lake Gen2) accounts

Author: yeongseon

docs/operations/backup-and-data-protection.md

@@ -6,13 +6,13 @@ Ensure data durability and availability using layered protection features.
 |---------|-------|---------|
 | Soft Delete | Container/Blob | Protect against accidental deletion. |
 | Versioning | Blob | Maintain history of blob changes. |
-| PIT Restore | Block blobs | Revert blob data to a specific point in time. |
+| PIT Restore | Standard GPv2, block blobs, hot/cool only | Revert blob data to a specific point in time. Not supported for HNS-enabled (Data Lake Gen2) accounts. |
 | Azure Backup | Blob containers / Azure Files | Operational or vaulted backup for blob data and file shares. |
 
 !!! note
     Enable soft delete as a minimum protection layer for all production storage accounts.
 
-Note: Point-in-time restore applies to block blobs only. Azure Backup also supports Azure Files through file share snapshots in a Recovery Services vault.
+Note: Point-in-time restore applies to Standard GPv2 accounts with block blobs in hot/cool tiers only, and is not supported for HNS-enabled (Data Lake Gen2) accounts. Azure Backup also supports Azure Files through file share snapshots in a Recovery Services vault.
 
 ```mermaid
 graph TD

docs/troubleshooting/data-protection-and-recovery-issues.md

@@ -12,7 +12,7 @@ Recover from accidental data deletion or corruption.
 !!! note
     Always verify which data protection features were enabled BEFORE the incident occurred.
 
-Note: Point-in-time restore applies to block blobs only. Azure Backup supports both Azure Blobs and Azure Files.
+Note: PITR requires standard GPv2 account, hot/cool tier, and is not supported with hierarchical namespace. Azure Backup supports both Azure Blobs and Azure Files.
 
 ```mermaid
 graph TD