Add storage_box playbook and fix HCLOUD_TOKEN extraction

- Add storage_box role: generates SSH key pair, creates Hetzner Storage
  Box with known password, installs public key via install-ssh-key,
  writes storagebox.yml to stack config. Idempotent: skips key install
  if SSH key auth already works.
- Add deploy.yml: one-shot playbook chaining provision → dns →
  storage_box → bootstrap → site for fresh deployments
- Fix .envrc HCLOUD_TOKEN extraction stripping surrounding quotes from
  vault YAML values
- Add restic_storagebox_password to vault template and setup.sh prompt
- Add sshpass to README prerequisites

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

requirements.yml

@@ -1,5 +1,5 @@
 ---
 collections:
   - name: hetzner.hcloud
-    version: ">=6.0.0"
+    version: ">=6.7.0"
   - name: ansible.posix