Retire a ServiceNow CI only when nothing depends on it

**Objective:** Decommission configuration item `{ci-name}` (reason: `{reason}`) and retire its matching asset, only when nothing still depends on it.

**Step 1: Read the CI**

Call `servicenow-get-configuration-item` with name `{ci-name}`. It must match exactly one record. Keep sys-id, class, install-status, operational-status and serial-number. If install-status is already Retired, stop.

**Step 2: Dependency checks**

* Call `servicenow-get-alert` with configuration-item `{ci-name}` and state Open.
* Call `servicenow-get-ci-affected` with configuration-item `{ci-name}`; read every CHG task with `servicenow-get-change-request` and keep open ones.
* Call `servicenow-get-impacted-ci` with configuration-item `{ci-name}` to see whether it is a service that tasks depend on.
* Call `servicenow-get-knowledge-related-product` with configuration-item `{ci-name}` for articles that will need updating.

Open alerts or open changes block the decommission: list them and stop unless the user explicitly overrides.

**Step 3: Find the asset**

If the CI has a serial-number, call `servicenow-get-asset` with serial-number set to it. Keep the asset sys-id and state.

**Step 4: Confirm**

Show: the CI, the dependency findings, the planned CI update (install-status Retired, operational-status Non-Operational) and the planned asset update (install-status Retired) if an asset was found. Ask for an explicit yes.

**Step 5: Write**

1. Call `servicenow-update-configuration-item` once with the CI sys-id, install-status Retired and operational-status Non-Operational.
2. If an asset was found, call `servicenow-update-asset` once with its sys-id, install-status Retired and comments "Decommissioned with CI `{ci-name}`. `{reason}`".

**Step 6: Verify and report**

Re-read both records and report their new statuses, plus the knowledge articles from Step 2 that mention this CI.

**Rules & Guidelines:**

* Write tools allowed: `servicenow-update-configuration-item` once and `servicenow-update-asset` once, after one confirmation. Do not call `servicenow-update-base-configuration-item`, `servicenow-update-ci-affected` or any add- tool.

**Validation:**

* If `{ci-name}` matches nothing, retry with name.contains, list the candidates and stop.