feat: Member Effectiveness Score + Representation Alignment View (v0.9.9)

Member Effectiveness Score
- New BillCosponsor table (migration 0018) with per-bill co-sponsor
  party data required for the bipartisan multiplier
- bill_category column on Bill (substantive | commemorative | administrative)
  set by a cheap one-shot LLM call after each brief is generated
- effectiveness_score / percentile / tier columns on Member
- New bill_classifier.py worker with 5 tasks:
    classify_bill_category  — triggered from llm_processor after brief
    fetch_bill_cosponsors   — triggered from congress_poller on new bill
    calculate_effectiveness_scores — nightly at 5 AM UTC
    backfill_bill_categories / backfill_all_bill_cosponsors — one-time
- Scoring: distance-traveled pts × bipartisan (1.5×) × substance (0.1×
  for commemorative) × leadership (1.2× for committee chairs)
- Percentile normalised within (seniority tier × party) buckets
- Effectiveness card on member detail page with colour-coded bar
- Admin panel: 3 new backfill/calculate controls in Maintenance section

Representation Alignment View
- New GET /api/alignment endpoint: cross-references user's stanced bill
  follows (pocket_veto/pocket_boost) with followed members' vote positions
- Efficient bulk queries — no N+1 loops
- New /alignment page with ranked member list and alignment bars
- Alignment added to sidebar nav (auth-required)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/lib/types.ts

@@ -51,6 +51,9 @@ export interface Member {
   leadership_json?: MemberLeadership[];
   sponsored_count?: number;
   cosponsored_count?: number;
+  effectiveness_score?: number;
+  effectiveness_percentile?: number;
+  effectiveness_tier?: string;
   latest_trend?: MemberTrendScore;
 }
 
@@ -119,6 +122,27 @@ export interface Bill {
   latest_trend?: TrendScore;
   updated_at?: string;
   has_document?: boolean;
+  bill_category?: string;
+}
+
+export interface AlignmentScore {
+  bioguide_id: string;
+  name: string;
+  party?: string;
+  state?: string;
+  chamber?: string;
+  photo_url?: string;
+  effectiveness_percentile?: number;
+  aligned: number;
+  opposed: number;
+  total: number;
+  alignment_pct?: number;
+}
+
+export interface AlignmentData {
+  members: AlignmentScore[];
+  total_bills_with_stance: number;
+  total_bills_with_votes: number;
 }
 
 export interface BillDetail extends Bill {