fix: correct misleading PVE 9 VM disk monitoring message (addresses #348)

The setup script was incorrectly claiming that VM disk monitoring works
on Proxmox 9 with API tokens. This is not true due to an upstream
Proxmox limitation where API tokens cannot access guest agent data
even with the correct permissions.

Updated the setup script to clearly explain:
- This is a known Proxmox 9 limitation, not a Pulse issue
- API tokens are blocked from accessing get-fsinfo
- Available workarounds (use root@pam or wait for upstream fix)
- Link to issue #348 for full context

This should prevent further confusion for users running Proxmox 9.

internal/api/config_handlers.go

@@ -2319,21 +2319,23 @@ else
     fi
     
     echo ""
-    echo "✓ VM Disk Monitoring on Proxmox 9"
-    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
-    echo "VM disk monitoring DOES work on Proxmox 9 with API tokens!"
+    echo "⚠ VM Disk Monitoring on Proxmox 9 - Known Limitation"
+    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+    echo "VM disk monitoring does NOT work on Proxmox 9 with API tokens"
+    echo "due to an upstream Proxmox limitation."
     echo ""
-    echo "The PVEAuditor role includes VM.GuestAgent.Audit permission"
-    echo "which allows reading guest agent data for disk usage."
+    echo "This is a known Proxmox 9 issue:"
+    echo "  • PVE 9 removed VM.Monitor permission"
+    echo "  • API tokens cannot access guest agent data (get-fsinfo)"
+    echo "  • Even with VM.GuestAgent.Audit permission, tokens are blocked"
+    echo "  • Proxmox's own web UI also shows 0% for VMs (bug #1373)"
     echo ""
-    echo "If VMs show zero disk usage:"
-    echo "  • Ensure qemu-guest-agent is installed and running in the VM"
-    echo "  • Check that the token has PVEAuditor role applied"
-    echo "  • Verify with: qm agent <VMID> get-fsinfo"
-    echo "  • Container (LXC) disk usage always works"
+    echo "Workarounds:"
+    echo "  • Use root@pam credentials instead of API tokens (if security allows)"
+    echo "  • Container (LXC) disk usage works fine with tokens"
+    echo "  • Wait for Proxmox to fix this upstream limitation"
     echo ""
-    echo "Note: qemu-guest-agent must be installed in VMs for any disk"
-    echo "monitoring to work. The data exists but token access is restricted."
+    echo "For more details, see: https://github.com/rcourtman/Pulse/issues/348"
 fi
 
 echo ""