Record the introduction commit in the session handoff

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/SESSION_HANDOFF.md

@@ -506,7 +506,8 @@ the device time instead of 10:00.
 Checks: 298 unit tests with the local ROM; native and reference builds;
 reference, vendor and release checks; `git diff --check`; 87
 Chromium/WebKit browser tests passed, 19 skipped intentionally (including
-the new intro flow and a reload during it, in both browsers). Not committed.
+the new intro flow and a reload during it, in both browsers). Committed and
+pushed to `main` as `b13fd20`.
 
 Next (PLAN section 2): player switching and non-ball items in battle; MOVE
 PKMN W/O MAIL and the stats screen with the party menu; a continuous opening