قراءة وظائف ERC⁦-8183⁩: المعرّف الذي يتجاوز jobCounter() لا يفشل، والمزوّد هو ownerOf(agentId) لا ecrecover

Two silent traps from reading every job on AgenticCommerce 0xEa4DAa3100A767e86FDed867729ae7446476EBA6: 1. getJob on an id that does not exist does NOT revert. It returns a zero structure that decodes as a perfectly plausible OPEN job with budget 0. A scan one step too far counts phantoms. Bound the range by jobCounter() and keep a row only if the structure echoes the id you asked for. 2. To find which agent a provider address is: ecrecover over the seller's provider_sig is wrong — raw digest and EIP-191 both gave addresses with no balance, no nonce, in no job. The provider is ownerOf(agentId) on the ERC-8004 IdentityRegistry (0x8004A169FB4a3325136EB29fA0ceB6D2e539a432). Also: sellers answer negotiate in two dialects — flat (provider, price, currency "U") and an envelope (negotiation_hash, provider_sig, response.terms.price, currency as the token address). Parse both. And the A2A endpoint comes from the card's url, not from guessing /a2a: some sellers serve A2A at the root and answer 404 on /a2a.