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>

tests/core/test_ansible_runs_page.py

@@ -92,7 +92,7 @@ async def test_ansible_pages_share_one_strip_of_tabs(app):
         page = await render_template("ansible/index.html", **_ctx([]))
     nav = page[page.index('<nav class="section-tabs" aria-label="Ansible">'):]
     nav = nav[:nav.index("</nav>")]
-    for href in ("/ansible/", "/ansible/playbooks", "/ansible/schedules", "/ansible/inventory/targets"):
+    for href in ("/ansible/", "/ansible/playbooks", "/ansible/schedules", "/ansible/inventory/"):
         assert f'href="{href}"' in nav, href
     assert nav.count('aria-current="page"') == 1 and '<a href="/ansible/" aria-current="page">Runs</a>' in nav
     assert "No runs yet." in page and "No runs in the last 30 days" in page