fix(planner): correct retry wall-clock formula + lock table contract

internal/planner/planner.go

@@ -456,8 +456,9 @@ func buildPlannedTask(planID, taskType string, planIndex int, params any) (seiv1
 }
 
 // taskMaxRetries is the executor's retry budget per task type. Default 0
-// makes the first ExecutionFailed terminal. Wall-clock per N retries:
-// 5s + 10s + 20s + 30s*(N-3) for N>=3.
+// makes the first ExecutionFailed terminal. Wall-clock per N retries
+// (RetryCount is incremented before retryBackoff is called):
+// 10s for N=1; 10s + 20s + 30s*(N-2) for N>=2.
 func taskMaxRetries(taskType string) int {
 	switch taskType {
 	case TaskConfigureGenesis:

internal/planner/planner_test.go

@@ -0,0 +1,18 @@
+package planner
+
+import "testing"
+
+func TestTaskMaxRetries(t *testing.T) {
+	cases := map[string]int{
+		TaskConfigureGenesis: genesisConfigureMaxRetries,
+		TaskAssembleGenesis:  groupAssemblyMaxRetries,
+		TaskDiscoverPeers:    discoverPeersMaxRetries,
+		"unknown-task-type":  0,
+		"":                   0,
+	}
+	for taskType, want := range cases {
+		if got := taskMaxRetries(taskType); got != want {
+			t.Errorf("taskMaxRetries(%q) = %d, want %d", taskType, got, want)
+		}
+	}
+}