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/README.md

@@ -5,8 +5,7 @@ libFuzzer targets for alkstore's parse/codec surfaces (see
 
 ## Layout
 
-- `fuzz_targets/` — one binary per target; thin `fuzz_target!` wrappers
-  (land with the wave-7 target tasks).
+- `fuzz_targets/` — one binary per target; thin `fuzz_target!` wrappers.
 - `shared/` — the invariant logic, as a plain library so normal
   `cargo test` (stable toolchain) can replay the committed corpora
   through the same invariants (`fuzz/shared/src/*.rs` `#[cfg(test)]`
@@ -14,9 +13,11 @@ libFuzzer targets for alkstore's parse/codec surfaces (see
   the shared crate is stable-clean. It consumes alkstore's public API
   only and must never become a dependency of any workspace crate.
 - `corpus/<target>/` — committed hand-made seeds (regenerate with
-  `python3 fuzz/gen_fuzz_seeds.py` from the repo root). Grown corpora
-  and artifacts are gitignored; each target task adds its `!`-negation
-  line when its corpus lands.
+  `python3 fuzz/gen_fuzz_seeds.py` from the repo root — must be a no-op
+  diff on the committed set) plus promoted campaign crash inputs
+  (`seed-900`+ numbering). Only `seed-*` files are tracked; grown
+  corpora (SHA-named units), artifacts, and coverage output are
+  gitignored and are **not** merged back into the committed seeds.
 - `run-detached.sh` — mandatory runner for agent sessions: wraps
   `cargo fuzz run` in `setsid` + `nohup` + log redirection so an OOM
   in a target can never take down the agent host (research doc §5).
@@ -27,7 +28,7 @@ libFuzzer targets for alkstore's parse/codec surfaces (see
 
 | Target | Drives | Invariants |
 |---|---|---|
-| `payload_codec` | `encode_payload` / `payload_as::<T>` (`alkstore/src/payload.rs`) | no-panic on any byte sequence; every decode failure typed `Error::Codec`; deep nesting loud at serde_json's recursion limit; `Value` round-trip (serde_json canonicalization pinned); typed round-trip for a representative payload set |
+| `payload_codec` | `encode_payload` / `payload_as::<T>` (`alkstore/src/payload.rs`) | no-panic on any byte sequence; every decode failure typed `Error::Codec`; deep nesting loud at serde_json's recursion limit; `Value` round-trip closes exactly outside `Number` float leaves, float leaves pinned to serde_json's default-parse drift bound (1–2 ULPs, see the research doc's implementation log — ADR-020 §4 pins default serde_json, not the `float_roundtrip` flavor); decode deterministic over stored bytes; typed round-trip for a representative payload set |
 | `every_parse` | the three `parse_every_interval` implementations (differential, through the engines' `#[doc(hidden)]` re-exports) + each engine's `skip_forward` boundary arithmetic | no-panic on any UTF-8-lossy string (each parser, each boundary path); typed rejection (`Error::InvalidSpec` on pg/mem, the substrate's error under its mapping on SQLite); three-way agreement on the Ok/Err partition and the `Ok` interval value (error identity not pinned — the SQLite `Result<i64, String>` vs `InvalidSpec` asymmetry is known); overflow posture: `skip_forward` over adversarial `(next_fire_at, now, interval)` triples rejects-or-saturates, never wraps or panics; the `n <= 0` and giant-`n` arms (leading zeros, digit overflow at exactly `i64::MAX/86400`, positive-zero rejection) |
 | `name_validation` | `validate_name` / `validate_shared_name` / `validate_local_name` (`alkstore/src/validation.rs`) | no-panic on any byte sequence (lossy-decoded and `arbitrary`-structured strings); deterministic accept/reject (double-invocation-pinned); rejection only via the typed taxonomy — `Error::InvalidName` for empty/whitespace-only on both kinds, `Error::ReservedName` for the leading byte-exact `__alkstore_` prefix on the shared kind only (the local kind takes the non-empty rule only, so a leading reserved prefix is legal there); the reserved-prefix rule exact in every casing/boundary form (casing deviations, missing trailing underscore, embedded and whitespace-led forms accept); the rejection carries the supplied name verbatim (names are not trimmed); verdict-class length-independence across the probed neighborhoods (0↔1, 11↔12, 63↔64, 4095↔4096, 65536) — no length cap is pinned (ADR-008 §4), so no length is ever a rejection cause |