fix(gates): the run address names the spec it implements, and why it has no baseline (#3471)

Hydra Gates has been red on development since #3462, on two findings that
are the same new file:

    [gate-16] spec-coverage:   1 changed method missing @SPEC
    [gate-26] visual-coverage: 1 new page component missing a visual baseline

Both are src/views/flows/FlowRunDetail.vue.

gate-16: `resolve()` now carries @SPEC pointing at the flow-runs-subject-scope
spec, which is where the deep link this page implements is written down: "the
run uuid in the row is the deep link to it". The path was opened and read
rather than guessed. A tag the gate accepts but that resolves to nothing
clears the finding without covering anything, and that is worth stating
because the gate cannot tell the difference.

gate-26: an @visual exclude with its reason, rather than a baseline. This
page has no screen. It is a resolver: the spinner is replaced by the flow
editor as soon as the run resolves, and the failure state is one
NcEmptyContent whose pixels say nothing the flow editor's own baselines do
not already cover.

WHAT IS STILL MISSING, PLAINLY. The behaviour here is worth a test and does
not have one: that a cold load of /flow-runs/{uuid} reaches the flow rather
than the manifest's catch-all, that Back does not bounce because the handover
replaces rather than pushes, and that an absent run says so at its own
address. I wrote that spec and could not run it: this workstation's instance
carries 30-odd apps and the shared global setup times out logging in at 30s,
twice, before any test starts. Rather than ship a playwright spec whose only
evidence is that it reads correctly, the exclude says what is not covered and
the comment in the file says what to write. The gap is named, not hidden.

Co-authored-by: Conduction Release Bot <release-bot@conduction.nl>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: 3 people

src/views/flows/FlowRunDetail.vue

@@ -21,6 +21,16 @@
   run uuid that does not resolve is usually a stale link from a ticket or a
   notification, and silently landing somebody on the dashboard is the
   behaviour that makes a dead link impossible to diagnose.
+
+  @visual exclude this page has no screen to baseline. Both of its states are
+  transient by design: the spinner is replaced by the flow editor as soon as
+  the run resolves, and the failure state is one NcEmptyContent whose pixels
+  say nothing the flow editor's own baselines do not already cover. What is
+  worth testing here is behaviour, not appearance — that a cold load of
+  /flow-runs/{uuid} reaches the flow rather than the manifest's catch-all,
+  that Back does not bounce because the handover replaces rather than pushes,
+  and that an absent run says so at its own address. That belongs in a
+  behavioural spec under tests/e2e/, and it is not written yet.
 -->
 <template>
 	<NcAppContent>
@@ -92,6 +102,10 @@ export default {
 		/**
 		 * Read the run, then hand over to its flow's editor.
 		 *
+		 * @spec openspec/changes/flow-runs-subject-scope/specs/flow-runs-subject-scope/spec.md
+		 *   "the run uuid in the row is the deep link to it" — this is the
+		 *   resolver that makes that uuid an address a browser can open.
+		 *
 		 * @return {Promise<void>}
 		 */
 		async resolve() {