fix(analysis): skip inherited expose_dict / collect_dict via __dict__ lookup (#292)

[allmonday]

Resolves #292.

Summary

_prepare_class_context read __pydantic_resolve_expose__ via getattr(kls, ..., {}), which walks the MRO. A subclass that inherits the attribute without overriding it gets the parent's dict, and _validate_expose then re-registers the same alias into self.expose_set — falsely raising ValueError: Expose alias name conflicts the moment both classes appear in the same resolve tree.

Trigger

class ExposeParent(BaseModel):
    __pydantic_resolve_expose__ = {'id': 'parent_id'}
    id: int
    siblings: list['ExposeChild'] = []   # forces walk into ExposeChild

class ExposeChild(BaseModel):
    name: str

await Resolver().resolve(ExposeParent(id=1, siblings=[]))
# pre-fix:  ValueError: Expose alias name conflicts
# post-fix: OK

The conflict doesn't fire when Child is the root (only one walk) — only when parent and child are both walked in the same tree.

Fix

- expose_dict = getattr(kls, const.EXPOSE_TO_DESCENDANT, {})
- collect_dict = getattr(kls, const.COLLECTOR_CONFIGURATION, {})
+ expose_dict = kls.__dict__.get(const.EXPOSE_TO_DESCENDANT, {})
+ collect_dict = kls.__dict__.get(const.COLLECTOR_CONFIGURATION, {})

kls.__dict__ only sees attributes defined directly on the class, so subclasses read {} unless they explicitly re-declare.

Symmetric change applied to collect_dict — that path doesn't currently false-positive (its check is by-reference and collect_set.add is idempotent), but the two lines are semantically identical and keeping them consistent prevents the same trap if collect validation logic changes later.

Test plan

• Added test_inherited_expose_does_not_conflict: ExposeParent with expose config + ExposeChild inheriting + parent has list[Child] field so both get walked. Pre-fix this raised; post-fix scan succeeds and child's expose_dict is {}.
• Original repro confirms: pre-fix raises, post-fix succeeds.
• `pytest tests/` — 781 passed, 1 skipped.
• `ruff check` — clean.

🤖 Generated with Claude Code