[wzul]

Problem

Two TypeError shapes were left over from the v2.1.1 sweep — the same class as #18 (a decoded response value reaching a typed parameter or return), just at different call sites. Both are reachable only if the gateway (or a proxy in front of it) answers with a shape the schema does not describe, which is exactly what happened with GET /public_key/.

1. A list entry that is not an object. Every paginated list model maps results through a closure typed fn (array $x):

$list->results = array_map(
    fn (array $w) => Webhook::fromArray($w),   // one non-object entry = TypeError
    $data['results'] ?? []
);

{"results": ["x"]} → TypeError: WebhookList::{closure}(): Argument #1 ($w) must be of type array, string given. One bad entry fails the whole page, including the entries that were fine.

2. A non-object body from the account endpoints.

$json = json_encode($response);
return json_decode($json !== false ? $json : '[]', true);   // declared : array

A string body round-trips to a string → TypeError: AccountResource::balance(): Return value must be of type array, string returned.

Changes

• lib/Model/{WebhookList,CompanyStatementList,ClientList,ClientRecurringTokenList}.php — filter results to arrays before mapping (array_filter($results, 'is_array') + array_values()); a missing/invalid results key still yields [] as before.
• lib/Model/Billing/{BillingTemplateList,BillingTemplateClientList}.php — same item filtering, keeping their existing null for an absent/invalid results key.
• lib/Resource/AccountResource.php — balance() and turnover() coerce a non-array decode to [].
• tests/ResponseShapeTest.php — four cases: a mixed list (one string + one valid object, asserts the valid entry still comes through), an all-invalid list, and both account methods against a string body.
• CHANGELOG.md — two ### Fixed entries under [Unreleased].

Verification

• composer test — 131 tests, 381 assertions, OK.
• composer phpstan — no errors (level 8 + bleedingEdge).
• composer cs-check — clean.
• The new tests bite: with lib/ reverted, all four fail with exactly
  WebhookList::{closure}(): Argument #1 ($w) must be of type array, string given,
  BillingTemplateList::{closure}(): Argument #1 ($r) must be of type array, string given,
  and AccountResource::balance()/turnover(): Return value must be of type array, string returned.

Potential Risks & Review Items

• Silent skipping vs. failing. A malformed entry is now dropped instead of exploding the page. That is the right trade for a list endpoint (and matches what a caller can act on), but it does mean a gateway regression that returns garbage results looks like an empty/short page rather than an error. results still carries every valid entry, and next/previous are untouched.
• Billing vs. other lists keep different "empty" semantics (null for an absent/invalid results key in the two billing models, [] in the rest). I preserved each model's existing behaviour rather than normalising them in this PR — worth a follow-up decision, but changing it here would be a silent API change.
• array_values() re-indexes the filtered results; previously the map preserved keys from results (which is always a JSON array, so indexes were already sequential).
• Changelog overlap with fix: wrap transport failures (DNS/connect/TLS/timeout) in a catchable NetworkException #20: that PR also edits the [Unreleased] section (adds ### Added for NetworkException). Whichever merges second will need a trivial rebase — flagging so it does not read as a surprise conflict.
• No version bump: both entries are under [Unreleased].