Transaction created successfully

Unauthorized. Two shapes: the shared auth / company-id guard (missing or invalid
Authorization, missing company-id) answers an empty body — branch on the
status code; the action-level guard (admin-only mutation, company-scope mismatch)
answers {"message": "Unauthorized (401)"}. Parse defensively (skip JSON.parse on
an empty body). See Errors.

Forbidden. Two guards:

• Not authorized to impute this transfer to the chosen budget — budget_id names a
  balance group you cannot operate for the sender account's holder (not the
  company-id header). Bare {"message": …}, no Validation failed: envelope.
• Capability guard on the resolved bank key:
  {"error": {"code": "banking/capability_missing", "capability": "...", "message": "..."}}.

Not found — an id in the body names no existing record: sender_id (or the deprecated
owner_id) matches no bank_account, or recipient_id matches no bank_recipient.
Do not read it as "not yours": a sender_id of another company, or an unresolvable
bank_key_id, is a 401. The body carries no field-level detail — resolve each id
first (GET /v1/banking/bank_accounts, GET /v1/banking/bank_recipients).

Unprocessable Entity — validation errors.

Response shape: {"message": "Validation failed: <reasons>"}, <reasons> being
the failed validations joined by , . Match on the fragment, not the whole
string — two failures at once produce one concatenated message. Guards marked
bare below render their message with no Validation failed: prefix.

Causes (the full rule behind each literal is on the request-body field it names):

• Recipient must belong to same account as transaction — enrolled in a different
  account; look it up with ?owner_id={sender_id} or enroll it in the sender.
• Recipient not approved — waived for payroll transfers and transition: null drafts.
• Recipient has been deleted — enroll it again.
• Description is invalid — characters outside the base class; at BCI also fires
  for accents.
• Description is too long (maximum is N characters) — the sending bank's cap.
• Description only allows alphanumeric characters — BICE, nothing survived its strip.
• Description must be FACT, followed by a space and 1 to 12 digits — BCI
  supplier payrolls.
• Amount can't be blank / Amount must be greater than 0.
• Amount must be less than or equal to N — interbank per-bank ceiling (see amount).
• Amount must be greater than or equal to 100 — BCP, the PEN floor of S/ 1,00.
• Idempotency has already been taken — reused within the owning account (= sender_id).
• Payroll status must be draft / Payroll transition must be null — payroll no
  longer editable.
• Budget can only be imputed to CLP wallet transfers, Budget is dissolved,
  Budget cannot be combined with a payroll, Budget must belong to the transfer's company, balance group has insufficient funds — budget_id guards; the last is
  attached to base, verbatim in lower case with no field prefix.
• Malformed budget id — bare. Not a well-formed UUID; checked before
  authorization, so bad input never masquerades as a 403.
• Lbtr is not yet implemented at bank {bank_id} /
  Lbtr cannot create lbtr transaction if the sender and recipient belong to the same bank.
• No manager found linking bank_key … to bank_account … — bare, {"error": …}
  body: the resolved bank key has no manager for the sending account.