feat: roll-call votes + granular alert filter fix (v0.9.5)

Roll-call votes:
- Migration 0017: bill_votes + member_vote_positions tables
- Fetch vote XML directly from House Clerk / Senate LIS URLs
  embedded in bill actions recordedVotes objects
- GET /api/bills/{id}/votes triggers background fetch on first view
- VotePanel on bill detail: yea/nay bar, result badge, followed
  member positions with Sen./Rep. title, party badge, and state

Alert filter fix:
- _should_dispatch returns True when alert_filters is None so users
  who haven't saved filters still receive all notifications

Authored-By: Jack Levy

backend/app/schemas/schemas.py

@@ -337,3 +337,34 @@ class CollectionDetailSchema(CollectionSchema):
 class BriefShareResponse(BaseModel):
     brief: BriefSchema
     bill: BillSchema
+
+
+# ── Votes ──────────────────────────────────────────────────────────────────────
+
+class MemberVotePositionSchema(BaseModel):
+    bioguide_id: Optional[str] = None
+    member_name: Optional[str] = None
+    party: Optional[str] = None
+    state: Optional[str] = None
+    position: str
+
+    model_config = {"from_attributes": True}
+
+
+class BillVoteSchema(BaseModel):
+    id: int
+    congress: int
+    chamber: str
+    session: int
+    roll_number: int
+    question: Optional[str] = None
+    description: Optional[str] = None
+    vote_date: Optional[date] = None
+    yeas: Optional[int] = None
+    nays: Optional[int] = None
+    not_voting: Optional[int] = None
+    result: Optional[str] = None
+    source_url: Optional[str] = None
+    positions: list[MemberVotePositionSchema] = []
+
+    model_config = {"from_attributes": True}