refactor: improve project structure, idempotency, and security

- Replace interactive python setup script with native Ansible vars_prompt.

- Add missing Prometheus helm values template for resource management on Raspberry Pi.

- Replace deprecated apt_key module usage with modern keyring file download.

- Add project files: requirements.txt, requirements.yml, and .gitignore.

playbook.yml

@@ -2,6 +2,15 @@
   hosts: pis
   become: yes
 
+  vars_prompt:
+    - name: target_ip
+      prompt: "Entrez l'IP du Raspberry Pi"
+      private: no
+    - name: target_user
+      prompt: "Entrez l'utilisateur SSH"
+      private: no
+      default: "pi"
+
   roles:
     - docker
     - k3s