nx_adnet_creative_gate.nx

nx_adnet_creative_gate.nx -- GATE for advertiser creative intake (nx_adnet_creative). Fixtures are synthesised IN this gate rather than read from disk, so it is an independent re-derivation: the gate builds a PNG header itself and asserts what the lib concludes about it. The load-bearing teeth are the two that protect a paying client and the host page: * CONTENT-ADDRESSING IS DETERMINISTIC AND SENSITIVE -- same bytes -> same url (idempotent re-upload), one byte different -> different url (replacing artwork mints a new url, so the creative can be served cacheable without ever going stale). * THE WEIGHT CEILING ACTUALLY REFUSES -- the four live house banners are 196,733 bytes each; if this tooth ever passes an oversize creative the platform silently re-admits that class. expect_exit: 0 license_tier: ORIGINAL