## Motivation
Every reindex reports `failure` at the purge step:
```
Purging BunnyCDN pull zone 3857050
Purged pull zone 3857050 (HTTP 204)
jq: error (at /tmp/tmp.eFPFmO:0): Cannot index array with string "Items"
Could not find BunnyCDN pull zone for hostname cran.allianceswisspass.devxy.io
```
`cran.rpkgs.com` purges fine. The Alliance zone never has, so it is still serving objects that rebuilds replaced, behind a ~370-day `cache_expiration_time`.
## The defect
```sh
jq -r '(.Items // .)[] | ...'
```
This was meant to accept both response shapes. It accepts neither: indexing an array with a string is an **error** in jq, not a null, so `//` never gets the chance to substitute and the whole expression aborts. The listing endpoint answers with a bare array for this account, so the lookup has always failed.
## Change
- Select the array explicitly by type instead of relying on `//` to absorb an error.
- Check the HTTP status of the listing call. It was previously used unconditionally, so an auth or rate-limit failure surfaced as "could not find hostname" — pointing at the wrong thing entirely.
- Fail when a hostname matches multiple zones rather than silently purging whichever jq emitted first.
- Request `perPage=1000`, so a paginated response cannot silently truncate the zone list.
## Verification
Ran the current `main` script and the fixed one against a stubbed `curl` returning an array-shaped listing:
```
=== BEFORE (main) ===
Purged pull zone 3857050 (HTTP 204)
jq: error (at ...): Cannot index array with string ("Items")
Could not find BunnyCDN pull zone for hostname cran.allianceswisspass.devxy.io
=== AFTER ===
Purged pull zone 3857050 (HTTP 204)
Purging BunnyCDN pull zone 222
Purged pull zone 222 (HTTP 204)
```
The jq expression was also checked against both an array-shaped and an object-shaped (`.Items`) response; the old one fails the array case, the new one handles both. `shellcheck` clean.
Reviewed-on: #178
pat-s
85295a9495