canonical_formats: structural VAST/DAAST entries never match a LegacyFormat model, because version extraction reads dicts only #1750

Summary

project_v1_format_to_declaration never matches the registry's VAST or DAAST structural entries when it is handed a LegacyFormat model. _v1_version_constraints (adcp/canonical_formats/v1_to_v2.py) reads versions only from a dict:

src = v1_format if isinstance(v1_format, dict) else None
if src is None:
    return out

_v1_asset_types right above it handles both dicts and models, so the asset types reach structural_match but the versions do not. Three of the seven structural entries in the bundled registry require a version, so all three fail for a model input:

Spec

static/schemas/source/registries/v1-canonical-mapping.json (3.2.7), match modes: "structural — match against the format's slot shape, asset types, and version constraints. The PRIMARY fallback for v1 wire traffic".

Reproduction (adcp 9.3.0)

from adcp.canonical_formats import project_v1_format_to_declaration
from adcp.types.legacy import LegacyFormat

raw = {
    "format_id": {"agent_url": "https://peer.example.com", "id": "acme_preroll"},
    "name": "Acme preroll",
    "assets": [{"item_type": "individual", "asset_id": "v", "asset_type": "vast",
                "required": True, "requirements": {"vast_version": "4.2"}}],
}
print(project_v1_format_to_declaration(raw).declaration.format_kind)                        # video_vast
print(project_v1_format_to_declaration(LegacyFormat.model_validate(raw)).declaration)  # None

The same declaration projects to video_vast as a dict and to nothing as a model. Any caller that holds a typed LegacyFormat (for example one read back from list_creative_formats) gets a fail-closed result for a VAST or DAAST format with no canonical that no glob names.

Expected

Read vast_version / vast_versions / daast_version / daast_versions from a model the same way as from a dict: from each individual asset's requirements (VastAssetRequirements, DaastAssetRequirements; daast_versions is a DaastVersions root model). The pinned LegacyFormat has no top-level version member, so the top-level lookup applies only to dict input.