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/s3_provision.yml

@@ -0,0 +1,28 @@
+---
+# Provision S3 Storage Bucket
+# Creates Incus S3-compatible storage bucket and outputs credentials to console
+#
+# Prerequisites:
+#   - User must be member of 'incus' group
+#   - Incus must be configured and accessible
+#
+# Usage:
+#   ansible-playbook provision_s3.yml -e bucket_name=casdoor
+
+- name: Provision S3 Storage Bucket
+  hosts: localhost
+  connection: local
+  gather_facts: false
+  
+  pre_tasks:
+    - name: Validate required parameters
+      ansible.builtin.assert:
+        that:
+          - bucket_name is defined
+          - bucket_name | length > 0
+        fail_msg: |
+          Missing required parameters. Usage:
+          ansible-playbook provision_s3.yml -e bucket_name=<name>
+  
+  roles:
+    - role: incus_storage_bucket