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]>

components/data-grids/gre-tunnels-data-grid.tsx

@@ -75,7 +75,7 @@ const STATUS_MAP: Record<GreStatus, { label: string; dot: string }> = {
 }
 
 function TunnelStatus({ status }: { status: GreStatus }) {
-  const s = STATUS_MAP[status]
+  const s = STATUS_MAP[status] ?? STATUS_MAP.degraded
   return (
     <span className="inline-flex items-center gap-1.5 text-sm">
       <span className={cn("size-1.5 rounded-full", s.dot)} />
@@ -208,14 +208,21 @@ function GreTunnelsDataGrid({
         cell: ({ row }) => {
           const t = row.original
           if (!t.ipsec) return <span className="text-xs text-muted-foreground">—</span>
+          const enc = t.ipsec.encAlg ? ENC_LABELS[t.ipsec.encAlg] : undefined
+          const auth = t.ipsec.authAlg ? AUTH_LABELS[t.ipsec.authAlg] : undefined
+          const dh = t.ipsec.dhGroup ? DH_LABELS[t.ipsec.dhGroup] : undefined
+          const ike = t.ipsec.ikeVersion ? IKE_LABELS[t.ipsec.ikeVersion] : undefined
+          if (!enc && !auth && !dh && !ike) {
+            return <span className="text-xs text-muted-foreground">PSK · auto</span>
+          }
           return (
             <div className="flex flex-col gap-0.5">
               <span className="text-xs font-mono">
-                {ENC_LABELS[t.ipsec.encAlg]} / {AUTH_LABELS[t.ipsec.authAlg]}
+                {[enc, auth].filter(Boolean).join(" / ") || "PSK"}
               </span>
               <span className="text-xs text-muted-foreground font-mono">
-                {DH_LABELS[t.ipsec.dhGroup].split(" ")[0]} · {IKE_LABELS[t.ipsec.ikeVersion]}
-                {t.ipsec.pfs && " · PFS"}
+                {[dh?.split(" ")[0], ike].filter(Boolean).join(" · ")}
+                {t.ipsec.pfs ? " · PFS" : ""}
               </span>
             </div>
           )