v1 plan: fix TestPinAndUnpin event assertion (positions -> order and content); note the finding

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/plans/v1/README.md

@@ -77,3 +77,9 @@ tools/run-plan.sh docs/plans/v1          # from a clean checkout on master
   files were protected and the rule was to stop. Owner's fault for the conflict; the model's
   deviation is noted. The corrected files now sit in `_files/internal/config/` as the reference
   copies for the reviewer's byte-exact check.
+- 2026-09-25, task 04: my `TestPinAndUnpin` asserted the pin event at exactly `len-3` and the
+  release event at `len-1`, but the task's own rules make acquires under a pin record events too,
+  so a faithful implementation produces `[new pin pin new new release]` and the assertion cannot
+  hold. Ornith spent its first ten minutes puzzling over exactly that. Test fault (mine): the
+  assertion now checks order and content (a pin event naming beta, followed later by a release),
+  not positions.

docs/plans/v1/_files/internal/lease/lease_test.go

@@ -217,9 +217,26 @@ func TestPinAndUnpin(t *testing.T) {
 	if host, _, _ := tbl.Acquire(k, []string{"alpha", "beta"}, t0.Add(4*time.Minute)); host != "beta" {
 		t.Errorf("after unpin the existing lease (on beta) simply continues: %q", host)
 	}
-	if got := p.reasons(); got[len(got)-3] != store.ReasonPin || got[len(got)-1] != store.ReasonRelease {
-		t.Errorf("events = %v, want a pin event and a release event", got)
+	// Events: a pin event naming beta must exist, and the unpin's release event must come after it.
+	// Acquires under the pin may record their own events in between; their number is not fixed here.
+	got := p.reasons()
+	pinAt, releaseAt := -1, -1
+	for i, r := range got {
+		if r == store.ReasonPin && pinAt < 0 {
+			pinAt = i
 		}
+		if r == store.ReasonRelease {
+			releaseAt = i
+		}
+	}
+	if pinAt < 0 || releaseAt < pinAt {
+		t.Errorf("events = %v, want a pin event followed later by a release event", got)
+	}
+	p.mu.Lock()
+	if pinAt >= 0 && p.events[pinAt].ToHost != "beta" {
+		t.Errorf("pin event = %+v, want ToHost beta", p.events[pinAt])
+	}
+	p.mu.Unlock()
 }
 
 func TestDrainKeepsExistingRefusesNew(t *testing.T) {