Tool runner: the cap's reason fails the call; the test proves the ending; the refused-answer limit keys on the caller's prefix and forgets old entries (issue 1966, review round 1)

Claude-Session: https://claude.ai/code/session_01NcbgfFfQ4Z9UE5jK32PmE5

node-tools/internal/bus/bus.go

@@ -1229,15 +1229,25 @@ func (c *Conn) answerRefused(err error) bool {
 	if len(m) < 2 || !strings.HasPrefix(strings.Trim(m[1], `"`), "_INBOX.") {
 		return false
 	}
+	// Keyed without the reply's last token (a new one per request), so a caller's burst is one line.
 	subject := strings.Trim(m[1], `"`)
+	if dot := strings.LastIndex(subject, "."); dot > len("_INBOX.") {
+		subject = subject[:dot]
+	}
 	c.mu.Lock()
 	if c.inboxSaid == nil {
 		c.inboxSaid = map[string]time.Time{}
 	}
-	last, seen := c.inboxSaid[subject]
-	say := !seen || time.Since(last) >= time.Minute
+	now := time.Now()
+	for k, at := range c.inboxSaid {
+		if now.Sub(at) >= time.Minute {
+			delete(c.inboxSaid, k)
+		}
+	}
+	_, seen := c.inboxSaid[subject]
+	say := !seen
 	if say {
-		c.inboxSaid[subject] = time.Now()
+		c.inboxSaid[subject] = now
 	}
 	c.mu.Unlock()
 	if say && c.Logf != nil {

node-tools/internal/bus/refused_test.go

@@ -94,17 +94,22 @@ func TestARefusedAnswerIsSaidOncePerMinute(t *testing.T) {
 	refuse := func(subject string) bool {
 		return c.answerRefused(fmt.Errorf("%w: Permissions Violation for Publish to %q", nats.ErrPermissionViolation, subject))
 	}
-	if !refuse("_INBOX.user.abc") || !refuse("_INBOX.user.abc") || !refuse("_INBOX.user.def") {
+	// A reply subject ends in a token new to every request: a burst under one prefix is one line.
+	if !refuse("_INBOX.user.abc.t1") || !refuse("_INBOX.user.abc.t2") || !refuse("_INBOX.user.def.t1") {
 		t.Fatal("a refused answer was not taken for one")
 	}
 	if len(said) != 2 {
-		t.Fatalf("want one line per subject, got %v", said)
+		t.Fatalf("want one line per caller, got %v", said)
 	}
 	c.inboxSaid["_INBOX.user.abc"] = time.Now().Add(-2 * time.Minute)
-	refuse("_INBOX.user.abc")
+	c.inboxSaid["_INBOX.user.old"] = time.Now().Add(-2 * time.Minute)
+	refuse("_INBOX.user.abc.t3")
 	if len(said) != 3 || !strings.Contains(said[2], "_INBOX.user.abc") {
 		t.Fatalf("a minute later it is said again, got %v", said)
 	}
+	if _, kept := c.inboxSaid["_INBOX.user.old"]; kept || len(c.inboxSaid) != 2 {
+		t.Fatalf("entries older than a minute are dropped on write, kept %v", c.inboxSaid)
+	}
 	if refuse("mesh.mod.x.tool.y") {
 		t.Fatal("a refused publish that is no answer was taken for one")
 	}