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/templates/ansible/_tabs.html

@@ -4,5 +4,5 @@
 {% macro ansible_tabs(active) -%}
 {{ section_tabs([("runs", "Runs", "/ansible/"), ("playbooks", "Playbooks", "/ansible/playbooks"),
                  ("schedules", "Schedules", "/ansible/schedules"),
-                 ("inventory", "Inventory", "/ansible/inventory/targets")], active, "Ansible") }}
+                 ("inventory", "Inventory", "/ansible/inventory/")], active, "Ansible") }}
 {%- endmacro %}