tracker: date every tester entry, and mark unknown-provenance ones (undated) rather than guessing. The build is cut per session, so the date implies the build -- which is what makes a Pass or Fail interpretable at all. Entries carried over from before the convention are marked (undated) = provenance unknown, not fresh evidence: the sheet was seeded from earlier tracking and nobody can now say which rows are original, so stamping them all with the session date would manufacture precision. That is exactly the error that produced the false 'still crashing after the fix' claim on #170 -- its row carries the same three timestamps and the same players as its own 2026-08-12 body, and whether that is a copy-forward or a genuine recurrence is STILL UNRESOLVED. 41 legacy entries relabelled (undated); 17 tester-dated entries left intact; header hover notes on both Tester Comments columns teach the convention in the sheet itself.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

context/playtest-tracker.md

@@ -72,10 +72,17 @@ know if it happens again". If the thread already answers it, do not ask again.
   routinely superseded, retracted, or already fixed by comment 4. Triaging 53 tickets from
   threads moved a third of the statuses and dropped P1 from 5 to 2. See
   [[reconstruction-gotchas]] for the general form of this mistake.
-- **Undated tester rows are historical.** Only rows explicitly prefixed with a date (`8/14 - `)
-  came from that session. Reading undated carried-forward rows as fresh evidence produced a false
-  "still crashing after the fix" report on #170 that had to be retracted across seven tickets.
-  Ask testers to date entries.
+- **DATE EVERY TESTER ENTRY: `M/D - ` at the front of each line.** The build is cut per session,
+  so the date implies the build — which is what makes a Pass or Fail interpretable at all.
+  Entries carried over from before this convention are marked **`(undated)`**, meaning
+  *provenance unknown — do not treat as fresh evidence*. That marker is deliberate: the sheet was
+  seeded from earlier tracking and nobody can now say which rows are original, so stamping them
+  all with the session date would manufacture precision. Reading undated rows as fresh already
+  produced a false "still crashing after the fix" claim on #170 that had to be retracted across
+  seven tickets — #170's row carries the same three timestamps and players as its own 2026-08-12
+  body, and whether that is a copy-forward or a genuine recurrence is STILL UNRESOLVED.
+  One entry per line, each with its own stamp; comment cells grow over time and undated text
+  running together is unreadable within two sessions.
 - **Never write `DONE` on OPEN.** A row that is done belongs on CLOSED; a `DONE` on the open page
   is a contradiction that confuses everyone reading it.
 - **Merge duplicates to one row per ticket** — linking loose reports to existing tickets creates