docs(webui): the gate record names the commit the gate was run at

The claim is checkable against a commit rather than against a tree: the
gates were run at 4e7efd4, and the only commits since are this record
and the inventory line it adds. It also records the repository's
capability suite, which the CI had called red: it passes here, so that
failure belongs to the macOS runner and not to this change.

Author: Fectivnfy112357

.plan/workspace-browser-tab/complete/gate-record.md

@@ -6,7 +6,9 @@ checked without running it again.
 
 **The run.** Every gate below was run on the tree that carries this record, in one sequence, in this
 order. The only files that changed after the run are this record and the inventory line it adds; no
-source file, no test and no document changed after it.
+source file, no test and no document changed after it. The run was made at `4e7efd43`; the only
+commits since are this record and the inventory line it adds, so the code the gates ran against is
+the code this tip carries. The gate was first run on that code at `4d247f43`.
 
 **The unit suite ran four more times** after the last of the fixes below, on the same tree: 208 files
 and 3230 tests, every time, with no unhandled errors. The gate had been red twice before that — once