fix(ui): walk the eleven dangling-style reports — two were real

#2444. Each needed reading rather than a batch fix, and the split was 2 real
losses, 4 false reports, 5 wrappers that are bare on purpose.

REAL:

  .system-card   was a flex row, and every child still says so —
                 .system-swatch and .system-actions are flex-shrink: 0,
                 .system-body and .system-form--inline are flex: 1.
                 align-items: flex-start is why the swatch carries
                 margin-top: 0.3rem: nudged onto the first line of text.
  .systems-list  no rule AT ALL, so the systems list rendered with browser
                 bullets and indent. Invisible to the check — see below.
  .graph-embed   the panel is a flex column whose header is flex-shrink: 0,
                 so this is the item that takes the remaining height. Without
                 it the `height: 100%` on the line below resolves against auto
                 and does nothing, which left the comment above it specifying
                 a rule that could not work.

FALSE REPORTS, and the checker was wrong rather than the code:

`.pane.empty` and `td.num` are base rules for the element that carries those
classes — the check read any compound with more than a lone class as a
modifier. It now records a compound's whole class SET and clears an element
carrying all of them, which is exact: recording the classes individually would
have cleared `.pane` everywhere on the strength of a rule that only applies
alongside `.empty`. Four reports gone, and a check with false reports is one
that gets skimmed.

BARE ON PURPOSE — .rb, .topic-group, .new-topic, .sub-list, .dash-head, and
both .detail-row rows. Each namespaces descendant rules and assumes nothing
about layout, which is the tell that separates them from a deleted base. All
seven now carry a comment saying so, so the next reader doesn't re-litigate
them and a NEW entry in the report means something actually changed.

Also recorded in the script: it cannot see a class with no rule anywhere, since
that is indistinguishable from a semantic-only hook. `.systems-list` was found
by reading the file beside a class that WAS half-styled.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UaYUaouG9jjhATyuxCKrQs

frontend/src/components/SystemsSection.vue

@@ -387,6 +387,41 @@ async function confirmDelete() {
 .system-textarea { resize: vertical; }
 
 .system-form-actions { display: flex; gap: 0.4rem; }
+
+/* RESTORED (#2444). Both lost their base rule to a CSS sweep; only the
+   `--archived` modifier and the `:hover .system-actions` reveal survived.
+   The card WAS a flex row and every child still says so — `.system-swatch`
+   and `.system-actions` are `flex-shrink: 0`, `.system-body` is `flex: 1`,
+   and `.system-form--inline` is `flex: 1`. `align-items: flex-start` is why
+   the swatch carries `margin-top: 0.3rem`: it is nudged onto the first line
+   of text rather than centred against the whole card.
+
+   The list had no rule at all, so it rendered with browser bullets and
+   indent — invisible to the dangling-style check, which can only see a class
+   that is PARTLY styled. A class with no rules anywhere looks exactly like a
+   semantic-only hook.
+
+   Surface values match `.system-form` above, which is the same card shape in
+   this file and the reason they can be recovered rather than guessed. */
+.systems-list {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 0.4rem;
+}
+
+.system-card {
+  display: flex;
+  align-items: flex-start;
+  gap: 0.6rem;
+  padding: 0.6rem 0.75rem;
+  background: var(--color-bg-card);
+  border: 1px solid var(--color-border);
+  border-radius: var(--radius-md);
+}
+
 .system-card--archived { opacity: 0.6; }
 
 .system-swatch {