fix(devx): an artifact-roster row either judges the diff or says plainly that it cannot (#16221)

* wip: roster checker-health split, reason ordering, docblock clause

* fix(devx): an artifact-roster row either judges the diff or says plainly that it cannot

The `--commands` roster block tells its reader to run its rows, and for some of
them running them yields a green that cannot fail for anything in the diff: the
invocation resolves to the checker's own `--self-test` and nothing else. Those
rows sat in the same list, in the same syntax, as rows whose green does grade
the diff.

The two named rows are self-test-only ON PURPOSE -- the half of each gate that
judges a pull request needs the event payload and runs in its own workflow -- so
the repair is to say so, not to change the script definitions. Rows are now
split by a derived predicate, with the marker on the row rather than only in a
caption, because consumers of this block grep rows.

The discriminator is resolved one hop through the manifest that DEFINES the
name: reading the printed command alone selects five rows and misses both rows
this is about, since a pnpm-spelled row carries the flag in its manifest entry.
An invocation this tool cannot resolve is named unclassified rather than
defaulted into either side.

Rider: the residue printer now names the refusal that actually fired for a bare
separator-less literal, by ordering that branch ahead of the extensionless-target
branch, with the refusal itself given one owner that `hintCovers` calls.
Reachability re-measured: 236 dead hints, 0 reaching the target branch.

Rider: one docblock clause in check-cross-package-test-inputs completes the
single-segment refusal's statement of the rule with its one exception.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vbw3RPgdtqesx4azk9SbW8

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: claude[bot]

scripts/check-cross-package-test-inputs.mjs

@@ -352,8 +352,13 @@ const REPO_ROOT = resolve(HERE, '..');
  * wrong file is worse than a vague one, because the dev follows it and finds
  * nothing to edit. Computing it from the module URL also keeps the string out
  * of this module body: `extractWatchHints` strips a leading `./` and then
- * refuses what is left for having no separator, so an import specifier scores
- * as no population while a repo-relative spelling would score as one.
+ * refuses what is left for having no separator -- with one exception, so that
+ * a reader reasoning from this sentence about some OTHER literal gets the
+ * right answer: a stripped literal that RESOLVES to a tracked DIRECTORY is
+ * re-admitted (`moduleRelativeDirectoryHint`), and that predicate refuses a
+ * tracked FILE explicitly. An import specifier resolves to a file, so it
+ * scores as no population structurally rather than by luck, while a
+ * repo-relative spelling would score as one.
  */
 const DECLARATION_FILE = relative(REPO_ROOT, fileURLToPath(new URL('./cross-package-test-inputs.mjs', import.meta.url)));