test(proxmox): verify pending update credential routing

An admin-browser update read does not establish access for the monitoring token. Cover the proxied target path, configured token, denial propagation and healthy endpoint retention. Remove the unsupported Sys.Audit diagnostic hint: endpoint access is determined by Proxmox, not general inventory access.

Change-source: pulse-maintainer
Contract-Neutral: Diagnostic wording and method-comment correction plus synthetic regression coverage only; no collection logic, public API, permission policy, freshness or counter semantics change.

internal/monitoring/monitor_polling_node_helpers.go

@@ -378,7 +378,7 @@ func (m *Monitor) applyNodePendingUpdates(ctx context.Context, instanceName stri
 					Err(err).
 					Str("node", node.Node).
 					Str("instance", instanceName).
-					Msg("Could not check pending apt updates (may require Sys.Audit permission)")
+					Msg("Could not check pending apt updates with configured Proxmox credentials")
 				modelNode.PendingUpdatesReason = pendingUpdatesFailureReason(err)
 				if hasCached {
 					modelNode.PendingUpdates = cached.count

pkg/proxmox/client.go

@@ -2944,7 +2944,9 @@ type AptPackage struct {
 }
 
 // GetNodePendingUpdates returns the list of pending apt updates for a node
-// Requires Sys.Audit permission on /nodes/{node}
+// Access is evaluated by Proxmox for the configured credential on /nodes/{node}.
+// Do not infer access from general node-audit permission; endpoint requirements
+// can differ from other monitoring reads.
 func (c *Client) GetNodePendingUpdates(ctx context.Context, node string) ([]AptPackage, error) {
 	resp, err := c.get(ctx, fmt.Sprintf("/nodes/%s/apt/update", node))
 	if err != nil {

pkg/proxmox/pending_updates_auth_routing_test.go

@@ -0,0 +1,64 @@
+package proxmox
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+)
+
+// A cluster entry endpoint may proxy a different target node. Neither the
+// selected endpoint nor its successful inventory read grants apt access.
+func TestClusterClient_PendingUpdatesConfiguredCredentialAndTarget(t *testing.T) {
+	for _, status := range []int{http.StatusOK, http.StatusForbidden} {
+		t.Run(fmt.Sprint(status), func(t *testing.T) {
+			var reads atomic.Int32
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if r.Method != http.MethodGet {
+					t.Errorf("unexpected method %s", r.Method)
+				}
+				if r.Header.Get("Authorization") != "PVEAPIToken=monitor@pve!readonly=synthetic" {
+					t.Error("configured token was not preserved")
+				}
+				if r.Header.Get("Cookie") != "" {
+					t.Error("unexpected browser/session credential")
+				}
+				w.Header().Set("Content-Type", "application/json")
+				switch r.URL.Path {
+				case "/api2/json/nodes":
+					fmt.Fprint(w, `{"data":[{"node":"entry","status":"online"},{"node":"target","status":"online"}]}`)
+				case "/api2/json/nodes/target/apt/update":
+					reads.Add(1)
+					w.WriteHeader(status)
+					if status == http.StatusOK {
+						fmt.Fprint(w, `{"data":[{"Package":"example","Version":"2"}]}`)
+					} else {
+						fmt.Fprint(w, `{"message":"Permission check failed"}`)
+					}
+				default:
+					t.Errorf("unexpected request path %s", r.URL.Path)
+					w.WriteHeader(http.StatusNotFound)
+				}
+			}))
+			defer server.Close()
+			cfg := ClientConfig{Host: server.URL, TokenName: "monitor@pve!readonly", TokenValue: "synthetic"}
+			cc := NewClusterClient("routing-test", cfg, []string{server.URL}, nil)
+			updates, err := cc.GetNodePendingUpdates(context.Background(), "target")
+			if status == http.StatusOK {
+				if err != nil || len(updates) != 1 || updates[0].Package != "example" {
+					t.Fatalf("unexpected successful result: %v, %v", updates, err)
+				}
+			} else if err == nil || extractStatusCode(err.Error()) != http.StatusForbidden || len(updates) != 0 {
+				t.Fatalf("denial not preserved: %v, %v", updates, err)
+			}
+			if reads.Load() != 1 {
+				t.Fatalf("apt reads = %d; expected one without auth retry", reads.Load())
+			}
+			if !cc.GetHealthStatus()[server.URL] {
+				t.Error("apt permission failure must not poison cluster endpoint health")
+			}
+		})
+	}
+}