✨ feat(infrastructure): introduce ansible deployment for taler services

- add ansible playbooks and roles for deploying taler exchange and merchant
- configure PostgreSQL, GNU Taler repositories, and services

🔧 chore(config): provide example env and gitignore for sensitive files

- create .env-example with placeholders for sensitive info
- add .gitignore entries for .env and common editor files

roles/common/tasks/main.yml

@@ -0,0 +1,17 @@
+---
+- name: Ensure apt cache is up to date
+  ansible.builtin.apt:
+    update_cache: true
+    cache_valid_time: 3600
+
+- name: Install base packages
+  ansible.builtin.apt:
+    name:
+      - gnupg2
+      - apt-transport-https
+      - ca-certificates
+      - curl
+      - logrotate
+      - python3-apt
+    state: present
+