docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

ansible/prometheus/deploy.yml

@@ -0,0 +1,82 @@
+---
+- name: Deploy Prometheus
+  hosts: ubuntu
+  become: true
+  tasks:
+  - name: Check if host has prometheus service
+    ansible.builtin.set_fact:
+      has_prometheus_service: "{{'prometheus' in services}}"
+
+  - name: Skip hosts without prometheus service
+    ansible.builtin.meta: end_host
+    when: not has_prometheus_service
+
+  - name: Install Prometheus
+    ansible.builtin.apt:
+      name: prometheus
+      state: present
+      update_cache: true
+
+  - name: Fix Prometheus directory permissions
+    ansible.builtin.file:
+      path: /var/lib/prometheus
+      owner: prometheus
+      group: prometheus
+      mode: '750'
+      recurse: true
+
+  - name: Create textfile collector directory
+    ansible.builtin.file:
+      path: /var/lib/prometheus/node-exporter
+      state: directory
+      owner: prometheus
+      group: prometheus
+      mode: '750'
+
+  - name: Template prometheus.yml to Prospero
+    ansible.builtin.template:
+      src: prometheus.yml.j2
+      dest: /etc/prometheus/prometheus.yml
+      owner: prometheus
+      group: prometheus
+      mode: '640'
+    notify: restart prometheus
+
+  - name: Template alert_rules.yml to Prospero
+    ansible.builtin.template:
+      src: alert_rules.yml.j2
+      dest: /etc/prometheus/alert_rules.yml
+      owner: prometheus
+      group: prometheus
+      mode: '640'
+    notify: restart prometheus
+
+  - name: Create Prometheus systemd override directory
+    ansible.builtin.file:
+      path: /etc/systemd/system/prometheus.service.d
+      state: directory
+      mode: '755'
+
+  - name: Enable remote write receiver
+    ansible.builtin.copy:
+      content: |
+        [Service]
+        ExecStart=
+        ExecStart=/usr/bin/prometheus --config.file=/etc/prometheus/prometheus.yml --storage.tsdb.path=/var/lib/prometheus/metrics2/ --web.console.templates=/etc/prometheus/consoles --web.console.libraries=/etc/prometheus/console_libraries --web.listen-address=0.0.0.0:9090 --web.external-url= --web.enable-remote-write-receiver
+      dest: /etc/systemd/system/prometheus.service.d/override.conf
+      mode: '644'
+    notify: restart prometheus
+
+  - name: Start and enable Prometheus service
+    ansible.builtin.systemd:
+      name: prometheus
+      state: started
+      enabled: true
+      daemon_reload: true
+      
+  handlers:
+  - name: restart prometheus
+    ansible.builtin.systemd:
+      name: prometheus
+      state: restarted
+      daemon_reload: true