load_codex_cli_credential copied tokens.account_id straight into CodexCliCredential.account_id with no type check. A Codex auth file whose account_id is JSON null therefore propagated None into CodexChatModel._account_id, and model_post_init raised TypeError: 'NoneType' object is not subscriptable on the account prefix in its log line. A numeric or boolean account_id slipped through the same way, reaching the ChatGPT-Account-ID header as a non-string.
Treat any non-string account_id as absent and fall back to the credential's empty-string default, matching how a missing account_id already behaves.
* fix(models): pair Codex invalid tool calls with their tool results
`_parse_response` parks a function_call whose `arguments` are not valid JSON
on `AIMessage.invalid_tool_calls`, keeping its id and name. `_convert_messages`
serialized only `msg.tool_calls`, so the placeholder ToolMessage that
`DanglingToolCallMiddleware` injects to answer that call was emitted as a
`function_call_output` whose call_id had no matching `function_call` item in
the same request. Responses requires that pairing, turning a recoverable
malformed call into a hard provider error.
Emit `invalid_tool_calls` alongside `tool_calls` as `function_call` items.
* fix(models): drop invalid tool calls that lack a name or call_id
InvalidToolCall fields are nullable, and serializing every invalid call as a
function_call item sends name: null and call_id: null for one that is missing
them, which the Responses schema does not accept. For a caller that reaches
_convert_messages without DanglingToolCallMiddleware, that turned a call the
old serializer dropped into a rejected request.
A call missing either field is now skipped, and its arguments fall back to
"{}" when they are neither an object nor a string. Skipping cannot orphan the
placeholder ToolMessage that this branch pairs the call with: the middleware
mints a synthetic id and a fallback name for exactly these calls before
serialization, so a call still missing them here has no placeholder.
