fuzz campaigns + gate: wave 7 close — three 15-min detached campaigns clean (payload_codegen finding harness-model: serde_json default f64 parse drifts 1-2 ULPs; invariant pinned to 2-ULP float-leaf drift + decode determinism, crash input promoted as payload_codec/seed-900), fuzz/.gitignore retightened to seed-* tracking, corpus-replay gate joins AGENTS.md verification list, research doc §9 implementation log, README finalized

fuzz/.gitignore

@@ -1,7 +1,13 @@
 target
 corpus/*
 !corpus/payload_codec
+corpus/payload_codec/*
+!corpus/payload_codec/seed-*
 !corpus/every_parse
+corpus/every_parse/*
+!corpus/every_parse/seed-*
 !corpus/name_validation
+corpus/name_validation/*
+!corpus/name_validation/seed-*
 artifacts
 coverage