docs: drop dated self-corrections

Remove dates and "this used to say X" framing from prose and comments.
What the tree does now is the only thing that matters; the history is in
git.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

client/src/test/kotlin/io/flamenet/client/BundleMergeTest.kt

@@ -6,7 +6,7 @@ import kotlin.test.assertEquals
 import kotlin.test.assertTrue
 
 /**
- * The multi-device fan-out rule (found 2026-08-29 in live two-device testing).
+ * The multi-device fan-out rule (found in live two-device testing).
  */
 class BundleMergeTest {
     private fun stub(id: String) =