Subscribe a company to monitoring

Subscribe a company (by numeric company_id from /companies/search) to ongoing monitoring. Alerts fire on new corporate events, status changes, dissolution, and new sanctions matches. If webhook_url is set, alerts POST to it (HMAC-SHA256 signed via X-Prometiam-Signature using the returned webhook_secret) and appear in GET /monitor. A dissolution alert fires when the company gets a dissolution date or, where the register gives none (Canada, Israel, Singapore, Taiwan, Romania, many US registrations), when its status becomes closed; the latter is dated by the check that first sees the closure and carries detail.date_basis = first_seen_closed (register when the register's date is used). Available for ES, GB, IE, PL, NO, FI, SE, BE, HR, DK, EE, SK, CH, LV, CY, RO, LT, CA, AU, JP, IL, SG, CO, TW, BR, CZ, DE and US (every live country except FR) — ES has the full corporate-event stream; GB alerts on status, dissolution, sanctions and corporate events (Companies House filings and Gazette notices); IE/PL/NO alert on register-change events (none before 14 Oct 2026) as well as status, dissolution and sanctions; FI/SE/BE/HR/DK/EE/SK/CH/LV/CY/RO/LT/CA/AU/JP/IL/SG/CO/TW/BR/CZ/DE/US alert on register-change events (dated when first seen in the register data (for the United States, the weekly read of the registers that first sees it)) as well as status, dissolution and sanctions.