feat(ssh)!: configure keys with filename and content

Accept SSH key content directly so callers no longer need role-specific
source directories. Update Molecule coverage and documentation.

BREAKING CHANGE: private_keys entries must be objects with filename and
content instead of file names. authorized_keys entries must provide
content alongside filename. Public keys are also written to ~/.ssh.

Co-authored-by: Copilot <copilot@github.com>

molecule/default/converge.yml

@@ -28,13 +28,17 @@
           - Host: "*"
             StrictHostKeyChecking: "no"
           authorized_keys:
-          - filename: molecule.pub
+          - filename: alice.pub
+            content: "{{ lookup('ansible.builtin.file', molecule_scenario_directory + '/files/ssh/authorized_keys/molecule.pub', rstrip=false) }}"
             command: "/usr/bin/true"
             envs:
             - key: EDITOR
               value: vi
+          - filename: alice-login.pub
+            content: "{{ lookup('ansible.builtin.file', molecule_scenario_directory + '/files/ssh/authorized_keys/molecule.pub', rstrip=false) }}"
           private_keys:
-          - molecule.ed25519.key
+          - filename: alice.ed25519.key
+            content: "{{ lookup('ansible.builtin.file', molecule_scenario_directory + '/files/ssh/private_keys/molecule.ed25519.key', rstrip=false) }}"
         netrc:
         - machine: hostname.local
           login: alice