feat(semaphore): rewrite role with rootful Podman Quadlet + PostgreSQL

Complete rewrite of the semaphore role. Supersedes three prior
iterations whose admin-user-creation logic was unreliable across
Semaphore CLI versions.

Architecture:
  - Rootful Podman Quadlet under /etc/containers/systemd/
  - Separate PostgreSQL 16-alpine container on a user-defined
    podman network (semaphore-net)
  - Named volumes for both data stores (semaphore_data,
    semaphore_postgres_data) so container recreation is
    non-destructive
  - Pinned image tags: semaphoreui/semaphore:v2.18.5-ansible2.16.5
    and postgres:16-alpine
  - Post-deploy HTTP health check fails the playbook if Semaphore
    doesn't respond on /api/ping within ~60s

Admin user creation remains intentionally manual after first deploy;
the role README documents the exact podman exec command.

Removes the duplicate deploy_semaphore.yml and the now-unneeded
cleanup_semaphore.yml; day1_deploy_semaphore.yml is the canonical
entry point.

ansible/playbooks/day1_deploy_semaphore.yml

@@ -1,22 +1,17 @@
 ---
-# ------------------------------------------------------------------------------
-# FILE: playbooks/day1_deploy_semaphore.yml
-# DESCRIPTION: Deploys Semaphore on imagineering
-#              Runs: common → docker-host → semaphore
+# ============================================================================
+# day1_deploy_semaphore.yml
+# ----------------------------------------------------------------------------
+# Deploys SemaphoreUI + PostgreSQL on the imagineering host (figment).
+# Run AFTER day0_linux_baseline.yml has been applied to the target.
 #
-# USAGE:
+# Usage:
 #   ansible-playbook -i inventory.yml playbooks/day1_deploy_semaphore.yml
-#
-# SECRETS REQUIRED IN VAULT (group_vars/all/vault):
-#   vault_semaphore_database_password
-#   vault_semaphore_admin_password
-#   vault_semaphore_access_key_encryption
-# ------------------------------------------------------------------------------
+# ============================================================================
 
-- name: Deploy Semaphore
+- name: Deploy SemaphoreUI on imagineering
   hosts: semaphore_server
   become: true
-
+  gather_facts: true
   roles:
-    - docker-host
     - semaphore