Closes#86. Closes#85.
These land together on purpose. Fixing the encoder alone changes nothing for the blobs already in the zone, because `emit` skips whatever is already present.
## #86 — the framing fix
`klauspost/compress` omits the zstd `Frame_Content_Size` field for inputs under 256 bytes, which the format permits. Reference libzstd never does, so the NWN client — which sizes its output buffer from `ZSTD_getFrameContentSize` and has therefore never met a frame without one — rejected roughly 6% of our blobs outright. Any single one stops a sync dead, so no client could complete a sync of the live manifest.
No encoder option changes this, so `compressBlob` re-headers the affected frames into the shape libzstd itself emits: `Single_Segment_flag` set, `Window_Descriptor` dropped, and the freed byte spent on a one-byte `Frame_Content_Size`. Same length in, same length out, and the same descriptor byte (`0x24`) the issue recorded from libzstd.
`compressBlob` then asserts its own output. An encoder upgrade that finds another way to omit the field would otherwise reproduce #86 in silence, and a blob is skipped by every later emit once written.
`emitter_version` goes to `2`, so `assemble` refuses to merge an index written by the encoder that omitted the field.
**Proved against the reference decoder, not just a round trip.** A real emitted 175-byte blob:
```
Frames Skips Compressed Uncompressed Ratio Check Filename
1 0 48 B 175 B 3.646 XXH64 frame.zst
c59d6620d4ffd4bf3fe73df43b19b7afcfe8fea4 - <- zstd -dc | sha1sum
c59d6620d4ffd4bf3fe73df43b19b7afcfe8fea4 <- the blob's own name
```
Before the fix that `Uncompressed` column was blank.
## #85 — `nwsync verify`
`crucible nwsync verify <manifest-sha1>` reads a manifest and its blobs back through the **public pull zone**, with no credential, because what matters is the bytes a client is served, edge behaviour included. Every distinct blob is decompressed and hashed; failures are reported per blob as missing / malformed framing / size mismatch / hash mismatch, and the exit code is 1.
- `--sample N` makes a routine check cheap against a manifest that is ~69,000 blobs and 15 GB; the default is a full sweep.
- `--base URL` / `NWSYNC_PULL_BASE` overrides the public host.
- The manifest is checked against its own sha1 before a single blob is fetched.
- `emit --verify` applies the same check where `emit` would otherwise trust presence, and replaces a stored blob that is not what its name claims. This is what makes the #86 blobs repairable.
## Why the existing checks missed this
Both new checks assert the **frame property**, not just a round trip. The conformance suite (#59) compares decompressed bytes, so a frame that decodes correctly passes regardless of its header; and the earlier zone audit decompressed 68 blobs with the `zstd` CLI, a *more* capable decoder than the client's, which certified exactly the blobs the client rejects.
## Checks
`make check` and `make smoke` green. Second commit is the fixes from a two-axis review of the first.
## Not in this PR
Three follow-ups, filed separately: the backfill has not been run, replacing a blob does not purge the pull-zone edge cache, and #85's runbook line belongs to `sow-platform`.
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Co-authored-by: vickydotbat <vickydotbat@tutamail.com>
Builds sow-tools#53. Format spec followed is the resolution comment of sow-platform#94, checked line by line against niv/neverwinter.nim at HEAD (`nwsync.nim`, `compressedbuf.nim`, `nwsync/private/libupdate.nim`).
## What lands
`crucible nwsync emit <artifact> --out DIR` — explodes one `.hak`/`.erf`, or one loose file such as the TLK, into NWSync blobs plus a NSYM v3 manifest covering only that artifact, with the same `.json` sidecar upstream writes. Blob path `data/sha1/<h0h1>/<h2h3>/<sha1>`, body in NWCompressedBuffer framing (magic `NSYC`, version 3, algorithm 2, uncompressed size, zstd header version 1, dictionary 0, raw zstd frame). The sha1 that names a blob is over the uncompressed bytes.
`crucible nwsync assemble --order NAMES --entries DIR --out DIR [--group-id N]` — merges the per-artifact manifests into one, reading no bulk data at all. Merge rule is resref shadowing, not concatenation: a resref in more than one artifact resolves to the earliest artifact in `--order`, which is how the game resolves it. `--group-id` stays caller-supplied (1 current, 2 testing; 0 is absent, matching upstream omitting a zero integer meta field).
Rules taken from upstream and not re-invented: `nss`/`ndb`/`gic` always skipped; an unresolvable restype is a hard error, not a skip; a resource over 15 MB fails closed; no `latest` file and no `.origin` file, ever. A `.mod` is refused outright — a persistent world publishes no module contents, so the module contributes no bytes.
## Two deliberate departures
- **Emitter version is its own field, not the build revision.** `emitter_version` is a constant bumped only when emitted bytes change. Keying the refuse-to-merge check on `created_with` would invalidate every published index on every unrelated crucible commit and force a re-emit of the whole 15 GB corpus — the opposite of "nothing downstream ever needs the hak again".
- **`SOURCE_DATE_EPOCH` pins the sidecar timestamp.** The manifest itself was already deterministic; the sidecar's `created` was not, against the determinism rule in `docs/consumer-contract.md`.
## Not in this PR, and why
- **Direct upload.** Only the local `--out` sink exists, which is the conformance path. The upload sink and the mid-hak-failure question are sow-tools#60, and the consumer wiring is #65.
- **The conformance run against upstream.** sow-tools#59 owns getting `nwn_nwsync_write` running and capturing reference output. The format here was read from upstream source rather than from its output, so the byte-for-byte manifest comparison and the after-decompression blob comparison still have to happen — that is what #59 is for. The tests in this PR check the layout against the spec, so a shared misreading would pass them.
- **The `artifacts/haks/sha256/<a>/<b>/<sha256>.nsym` location.** emit writes `<out>/<name>.nsym`; where a publisher puts it is the publisher's business (#65).
- **The acceptance gate** — a real client syncing from an assembled manifest — is unchanged and still open.
## Checks
`make check` green (vet, unit tests, shellcheck, yamllint, workflow contract), `make smoke` green with the new builder, `nix build .#crucible` produces `crucible-nwsync`.
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Co-authored-by: vickydotbat <vickydotbat@tutamail.com>
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