feat(gre): enhance GRE tunnel status handling and IPsec configuration

- Introduced a new `greStatusMeta` function to streamline status retrieval and default handling.
- Updated GRE tunnel command generation to improve IPsec configuration handling, including optional fields for encryption and authentication algorithms.
- Enhanced the GRE tunnels data grid to display IPsec settings more clearly, including handling cases where certain parameters may be undefined.
- Refactored status display logic in the GRE page to utilize the new status meta function for consistency.

Co-authored-by: Cursor <[email protected]>

lib/data.ts

@@ -531,12 +531,13 @@ export type DscpMode = "inherit" | number
 
 export interface GreIpsec {
   secret: string          // ipsec-secret → auto-creates peer+policy+proposal
-  encAlg: IpsecEncAlg    // proposal enc-algorithms
-  authAlg: IpsecAuthAlg  // proposal auth-algorithms
-  dhGroup: IpsecDhGroup  // proposal pfs-group / peer dh-group
-  ikeVersion: IkeVersion // peer exchange-mode
-  lifetime: string       // proposal lifetime (e.g. "1d 00:00:00")
-  pfs: boolean           // perfect forward secrecy
+  /** Live CHR отдаёт только secret; proposal-поля есть у моков / формы */
+  encAlg?: IpsecEncAlg
+  authAlg?: IpsecAuthAlg
+  dhGroup?: IpsecDhGroup
+  ikeVersion?: IkeVersion
+  lifetime?: string
+  pfs?: boolean
 }
 
 export interface GreTunnel {