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

frontend/lib/types.ts

@@ -199,6 +199,31 @@ export interface CollectionDetail extends Collection {
   bills: Bill[];
 }
 
+export interface MemberVotePosition {
+  bioguide_id?: string;
+  member_name?: string;
+  party?: string;
+  state?: string;
+  position: string;
+}
+
+export interface BillVote {
+  id: number;
+  congress: number;
+  chamber: string;
+  session: number;
+  roll_number: number;
+  question?: string;
+  description?: string;
+  vote_date?: string;
+  yeas?: number;
+  nays?: number;
+  not_voting?: number;
+  result?: string;
+  source_url?: string;
+  positions: MemberVotePosition[];
+}
+
 export interface NotificationEvent {
   id: number;
   bill_id: string;