GRM-16: test: add molecule lifecycle scenarios, integration tests, and docs

- Add multi-instance molecule scenario verifying isolated data/config dirs
- Add lifecycle molecule scenario testing stop/disable/enable/start sequence
- Update default and binary verify playbooks for template unit assertions
- Add integration tests for full CLI lifecycle and multi-instance support
- Add pytest integration marker and --no-cov Makefile target
- Update README with lifecycle commands, multi-instance examples, and architecture
- Update Makefile with start/stop/enable/disable/status/remove targets
- Update .env.example with GRM_LANG documentation

ansible/roles/gitea-runner/molecule/binary/verify.yml

@@ -22,16 +22,27 @@
       ansible.builtin.command: docker --version
       changed_when: false
 
-    - name: Check systemd service file exists
+    - name: Check systemd template unit exists
       ansible.builtin.stat:
-        path: "/etc/systemd/system/gitea-runner-molecule-test-runner.service"
+        path: "/etc/systemd/system/gitea-runner@.service"
       register: service_stat
 
-    - name: Assert service file exists
+    - name: Assert template unit exists
       ansible.builtin.assert:
         that:
           - service_stat.stat.exists
-        fail_msg: "Systemd service file is missing"
+        fail_msg: "Systemd template unit is missing"
+
+    - name: Check instance data directory exists
+      ansible.builtin.stat:
+        path: "{{ gitea_runner_data_dir }}"
+      register: data_dir_stat
+
+    - name: Assert instance data directory exists
+      ansible.builtin.assert:
+        that:
+          - data_dir_stat.stat.exists
+        fail_msg: "Instance data directory is missing"
 
     - name: Check prune timer exists
       ansible.builtin.stat: