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/argos/stage.yml

@@ -0,0 +1,34 @@
+---
+- name: Stage Argos release tarball
+  hosts: localhost
+  gather_facts: false
+  vars:
+    argos_repo_dir: "{{repo_dir}}/argos"
+    archive_path: "{{rel_dir}}/argos_{{argos_rel}}.tar"
+
+  tasks:
+    - name: Ensure release directory exists
+      file:
+        path: "{{rel_dir}}"
+        state: directory
+        mode: '755'
+
+    - name: Fetch all remote branches and tags
+      ansible.builtin.command: git fetch --all
+      args:
+        chdir: "{{argos_repo_dir}}"
+
+    - name: Git pull
+      ansible.builtin.command: git pull
+      args:
+        chdir: "{{argos_repo_dir}}"
+
+    - name: Checkout specified argos release branch or tag
+      ansible.builtin.command: git checkout "{{argos_rel}}"
+      args:
+        chdir: "{{argos_repo_dir}}"
+
+    - name: Create argos archive for specified release
+      ansible.builtin.command: git archive -o "{{archive_path}}" "{{argos_rel}}"
+      args:
+        chdir: "{{argos_repo_dir}}"