chore: include complete dc refactor implementation and audits

internal/cluster/manager_test.go

@@ -0,0 +1,52 @@
+package cluster
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestNodeOperationGateAllowsReadsAndSerializesWrites(t *testing.T) {
+	n := &Node{}
+	release1 := n.acquireOperation("file_read")
+	done := make(chan struct{})
+	go func() { release2 := n.acquireOperation("edit_block"); close(done); release2() }()
+	select {
+	case <-done:
+		t.Fatal("write entered while read active")
+	case <-time.After(50 * time.Millisecond):
+	}
+	release1()
+	select {
+	case <-done:
+	case <-time.After(time.Second):
+		t.Fatal("write did not proceed")
+	}
+}
+func TestNodeOperationGateAllowsConcurrentReads(t *testing.T) {
+	n := &Node{}
+	var wg sync.WaitGroup
+	wg.Add(2)
+	for i := 0; i < 2; i++ {
+		go func() {
+			defer wg.Done()
+			release := n.acquireOperation("file_read")
+			time.Sleep(30 * time.Millisecond)
+			release()
+		}()
+	}
+	done := make(chan struct{})
+	go func() { wg.Wait(); close(done) }()
+	select {
+	case <-done:
+	case <-time.After(time.Second):
+		t.Fatal("reads did not complete")
+	}
+}
+func TestOperationRiskUnknownFailsClosed(t *testing.T) {
+	if operationRisk("unknown-danger") != 3 {
+		t.Fatal("unknown action must be high risk")
+	}
+	_ = context.Background()
+}