* Add craft-pcraft-format: the envelope of PhotoCraft's .pcraft bundle
The manifest around the document, with the document as a type parameter
(Manifest<D>), TileRef, the bundle's entry paths and hash check,
FORMAT_VERSION, the manifest decode limits with the nesting and item
scan, and the migration runner as a generic step list. Messages and
serialized field order are PhotoCraft's, so its saved manifests stay
byte-identical when it switches to these types.
Part of #59.
* ci: do not keep the checkout token in the pcraft-format workflow
The checkout step sets persist-credentials: false, as jpeg.yml and media.yml do. No later step in the job uses the token.
* pcraft-format: build no entry name from an invalid hash
tile_path and blob_path return None unless the hash is 64 lowercase hex
digits, so a hash read from a file such as "../x" never becomes an entry
name. TileRef::path gives a tile's entry the same way.
The docs note that MAX_GROUP_DEPTH is a copy of PhotoCraft's constant,
and that check_manifest also refuses a manifest larger than
max_manifest_bytes, which PhotoCraft's check before a save does not.
* ci: pin actions/checkout by commit and Rust to 1.95 in the pcraft-format workflow
* pcraft-format: read_manifest is the one reader of a manifest
read_manifest(json, limits, steps, target) checks the JSON against the
limits, refuses a format_version newer than target, runs the migration
steps, and reads the document as D and the other envelope members.
read_manifest_with reads the document with the caller's function
instead. Manifest no longer implements Deserialize.
Error::TooNew holds the manifest's generator, so a message can name the
writer; its message is unchanged. TooNew, Manifest and TileRef are
#[non_exhaustive], and Manifest::new and TileRef::new build them.
TILES_DIR, BLOBS_DIR, COMPOSITE_DIR and OBJECT_SUFFIX name the bundle's
directories and the object suffix. The docs of max_blob_bytes and
max_total_bytes say the caller enforces them.
* pcraft-format: read_manifest reports errors in serde's struct order
read_manifest reads the envelope members and the document in the order
the parsed object holds them, and reports a missing member after the
members that are present. A manifest with several faults gives the same
error as a derived Deserialize of the whole manifest, as PhotoCraft
reads it today.
* pcraft-format: document that a missing or invalid format_version is Corrupt
read_manifest's docs and the README say that a missing or invalid
format_version gives Error::Corrupt from migrate, and that a missing
generator or document, or any other mistyped member, gives Error::Json.
A test covers a string and a fractional format_version.
* pcraft-format: read_manifest refuses preview names other than its own
A manifest's `thumbnail` and `composite` named any entry the reader then
opened, while tile entries go through `is_valid_hash`. `read_manifest`
now gives `Error::Corrupt` for a `thumbnail` other than `thumb.png` or a
`composite` other than `composite/preview.png`, the only names PhotoCraft
writes. The check runs after the members are read, so JSON errors keep
their order.
The reader's doc now says a missing or invalid `format_version` is
`Error::Corrupt`, from `migrate`, not `Error::Json`.
FredApps