feat(ansible): Inventory on one page, add behind dialogs, delete behind the confirm (#5333)

/ansible/inventory/ shows every target (address, its linked Steward host,
its groups) and every group (members, the schedules aimed at it) under a
verdict line. The whole row opens the target or group. Add target and
Add group open small dialogs; a failed add comes back with its dialog
open and what was typed. The red x leaves the rows: Delete is on the
target's or group's page, behind the confirm dialog, saying which
schedules would be left with nothing to run on.

The two list pages (/inventory/targets, /inventory/groups) are gone
with no redirect (rule 122); their URLs keep only the Add POST.

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

steward/static/steward.css

@@ -216,6 +216,8 @@ strong, b, th { font-weight: 500; }
 .table tr.row-link { position: relative; cursor: pointer; }
 .table tr.row-link .row-target::after { content: ""; position: absolute; inset: 0; }
 .table tr.row-link .td-actions { position: relative; z-index: 1; cursor: auto; }
+/* A second link inside a row that opens as a whole: it sits above the row's target. */
+.table tr.row-link .row-inner { position: relative; z-index: 1; }
 .table td.nowrap { white-space: nowrap; }
 .cell-note { font-size: 0.78rem; color: var(--text-muted); margin-top: 0.2rem; }
 /* An alert episode's own transitions, folded under it (#5316). */
@@ -434,6 +436,8 @@ a.stat-tile:hover { border-color: var(--border-mid); background: var(--bg-elevat
 .form-section > .section-title { margin-bottom: 0.9rem; }
 .form-pair { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(14rem, 100%), 1fr)); gap: 0 1rem; }
 .form-pair[hidden] { display: none; }
+/* A column of checkboxes: a target's groups, a group's members. */
+.check-list { display: grid; gap: 0.4rem; }
 .ansible-fields { padding: 0.9rem 1rem 0.25rem; margin-bottom: 0.75rem; border: 1px solid var(--border); border-radius: var(--fs-radius-md); background: var(--bg-elevated); }
 .form-actions { display: flex; gap: 0.75rem; margin: 0.5rem 0 1.5rem; }
 .danger-zone { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap;