Tests put back the package state they set, so a loaded check machine trips no leaked bound

The check of release sdk1 failed on TestStatePutWritesAKeyWhole: TestACallIsAskedAgainOnlyWhenItReachedNoOne
left busretry's Bound at 50 ms, and on a loaded machine the state test's first pause overran it. Second failure
of the kind "tests leave package-level state set".

Quick fix: restore busretry's waits in the one test and lengthen the state test's bound.
Thorough fix (chosen, the kind met twice): busretry.Waits sets the waits and returns their restore, used as
t.Cleanup(busretry.Waits(...)) by every test that sets them, each with a bound of seconds where it waits to
succeed; and servesAlone gives every test that serves its own runtime channel and Served, put back after it,
instead of tests clearing the channel an earlier one left. A scan of every test assignment to a package-level
variable found no other unrestored one.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

go/process/call_test.go

@@ -103,7 +103,7 @@ func TestCallOnRefusesANodeThatIsNotOneToken(t *testing.T) {
 // The review of 2026-10-30 (issue 774): a callee's own answer is delivered, whatever its words, and is never asked
 // again during a blackout; only the transport's no responders is.
 func TestACallIsAskedAgainOnlyWhenItReachedNoOne(t *testing.T) {
-	busretry.Bound, busretry.FirstWait, busretry.MostWait = 50*time.Millisecond, time.Millisecond, 2*time.Millisecond
+	t.Cleanup(busretry.Waits(10*time.Second, time.Millisecond, 2*time.Millisecond))
 	for _, row := range []struct {
 		name   string
 		answer []error // per ask; the last repeats

go/process/state_test.go

@@ -208,7 +208,7 @@ func TestStatePutWritesAKeyWhole(t *testing.T) {
 		t.Fatalf("Get after Put: %+v, %v", e, err)
 	}
 	// Issue 774: a bus that answers nothing for a moment (a user-list reload) is waited out, not a lost write.
-	busretry.FirstWait = time.Millisecond
+	t.Cleanup(busretry.Waits(10*time.Second, time.Millisecond, 2*time.Millisecond))
 	kv, blackedOut := newFakeKV(), 2
 	dark := State{Module: "mesh-mail", Name: "sends", kv: func(context.Context) (jetstream.KeyValue, error) {
 		if blackedOut > 0 {