Raise one ServiceNow change for a finished Jira release

**Objective:** Raise one ServiceNow change request to deploy the finished Jira issues in project `{project-key}` (or only the keys in `{issue-keys}`, comma separated), planned to start on `{planned-start}` (default: ask the user). Write nothing until the user confirms.

**Step 1: Collect the Jira work**

If `{issue-keys}` is given, call `jira-get-issue` filtered by `issue-key` for each key. Otherwise call `jira-get-issue` with `project-key` set to `{project-key}` and `status` set to Done. Drop any issue whose summary or labels already carry a change number (CHG followed by digits) and list those separately as already covered. If nothing is left, say so and stop.

**Step 2: Check ServiceNow for an existing change**

Call `servicenow-get-change-request` with `short-description.contains` set to `{project-key}` and keep any that are not Closed or Canceled. If one already covers this release, show it and ask the user whether to continue with a new change; stop if they say no.

**Step 3: Confirm**

Draft the change: short description "Deploy {project-key}: <n> Jira issues", a description listing every Jira key with its summary and type, start date `{planned-start}`, and type Normal unless the user says otherwise. Show the draft and the list of Jira issues you will tag. Ask for confirmation. Do not continue without an explicit yes.

**Step 4: Write**

1. Call `servicenow-add-change-request` once with `short-description`, `description`, `type` and `start-date`.
2. Call `servicenow-get-change-request` with `short-description.contains` set to the short description you used, to read the new change `number`.
3. For each Jira issue, call `jira-add-issue-comment` once with the body "Deployed by ServiceNow change <change number>". Pass the issue key as `issue-id`.

**Step 5: Report**

The change number, its planned start, and a table of the Jira keys that were tagged and any that failed.

**Rules & Guidelines:**

* `servicenow-get-change-request` and `servicenow-add-change-request` are on the servicenow server. `jira-get-issue` and `jira-add-issue-comment` are on the jira server.
* Create exactly one change request. Do not call `servicenow-update-change-request`, `servicenow-add-change-task`, `jira-update-issue` or `jira-assign-issue`.

**Validation:**

* If `servicenow-add-change-request` fails, report the error and do not comment on any Jira issue.
* If the new change number cannot be read back, report that the change was created but not found, and do not comment on Jira.
* If a Jira comment rejects the key as `issue-id`, read the numeric id with `jira-get-issue-watcher` filtered by `issue-key` and retry once; otherwise record that issue as failed and continue.