feat(doctor): X6 (part) — shared-services ledger probe (spec 13) (#48)

Complete the X6 probe set: doctor now reports the shared-service ledger summary
(instance count + total ref rows), reusing the already-open state DB. Joins the
trust + dns probes for the full self-verification matrix. The safe `--fix`
(reconcile-only) is the remaining X6 piece.

Test: doctor --json lists the "shared services" probe.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: gustavobertoi

internal/cli/doctor.go

@@ -134,8 +134,19 @@ func runDoctor(cmd *cobra.Command) []docker.Check {
 		})
 	} else {
 		v, _ := db.SchemaVersion()
-		db.Close()
 		checks = append(checks, docker.Check{Name: "state ledger", Status: docker.StatusOK, Detail: fmt.Sprintf("schema v%d @ %s", v, ctxName)})
+		// Shared-service ledger summary (informational): instances + total refs.
+		shared, _ := db.ListSharedServices()
+		totalRefs := 0
+		for _, s := range shared {
+			n, _ := db.RefCount(s.Name)
+			totalRefs += n
+		}
+		db.Close()
+		checks = append(checks, docker.Check{
+			Name: "shared services", Status: docker.StatusOK,
+			Detail: fmt.Sprintf("%d instance(s), %d ref(s)", len(shared), totalRefs),
+		})
 	}
 
 	// DNS entries for *.localhost (spec 05) — best-effort, only when the current

internal/cli/gc_test.go

@@ -59,3 +59,15 @@ func TestDoctorIncludesTrustProbe(t *testing.T) {
 		t.Errorf("doctor --json missing the trust probe:\n%s", out.String())
 	}
 }
+
+func TestDoctorIncludesSharedProbe(t *testing.T) {
+	var out strings.Builder
+	root := NewRootCmd(Options{})
+	root.SetArgs([]string{"doctor", "--json"})
+	root.SetOut(&out)
+	root.SetErr(&out)
+	_ = root.Execute()
+	if !strings.Contains(out.String(), `"shared services"`) {
+		t.Errorf("doctor --json missing the shared-services probe:\n%s", out.String())
+	}
+}