[v0.9.1] Validator decoupled from hatch_metadata.json file I/O

[LittleCoinCoin]

Overview

Patch release introducing an optional metadata keyword argument to
validate_package(). Allows callers to supply a pre-extracted flat dict and
bypass disk I/O entirely — the groundwork required for Hatch CLI's upcoming
migration from hatch_metadata.json to server.json as the package
descriptor.

---

Bug Fixes

validate_package() hardcoded dependency on hatch_metadata.json

Root cause: validate_package() unconditionally loads hatch_metadata.json
from package_dir. Once Hatch CLI migrates to server.json, that file no
longer exists and every call fails with "hatch_metadata.json not found" —
with no way for the caller to supply already-extracted metadata.

Solution: Added metadata: Optional[Dict[str, Any]] = None between
package_dir and pending_update in the signature of
HatchPackageValidator.validate_package():

# Before
def validate_package(
    self,
    package_dir: Path,
    pending_update: Optional[Tuple[str, Dict]] = None,
) -> Tuple[bool, Dict[str, Any]]:

# After
def validate_package(
    self,
    package_dir: Path,
    metadata: Optional[Dict[str, Any]] = None,
    pending_update: Optional[Tuple[str, Dict]] = None,
) -> Tuple[bool, Dict[str, Any]]:

When metadata is supplied, the file-loading block is skipped entirely. When
absent (the default), the existing hatch_metadata.json path runs unchanged —
all current callers are backward compatible with no modifications required.

New caller pattern (Hatch CLI after server.json migration):

metadata = load_package_metadata(pkg_dir)  # extracts + merges from server.json
is_valid, results = validator.validate_package(pkg_dir, metadata=metadata)

Backward compat — existing callers unchanged:

# Still works exactly as before
is_valid, results = validator.validate_package(package_path)