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/api.ts

@@ -1,5 +1,6 @@
 import axios from "axios";
 import type {
+  AlignmentData,
   Bill,
   BillAction,
   BillDetail,
@@ -303,4 +304,16 @@ export const adminAPI = {
     apiClient.get<{ status: string; batch_id?: string; doc_count?: number; submitted_at?: string }>(
       "/api/admin/llm-batch-status"
     ).then((r) => r.data),
+  backfillCosponsors: () =>
+    apiClient.post("/api/admin/backfill-cosponsors").then((r) => r.data),
+  backfillCategories: () =>
+    apiClient.post("/api/admin/backfill-categories").then((r) => r.data),
+  calculateEffectiveness: () =>
+    apiClient.post("/api/admin/calculate-effectiveness").then((r) => r.data),
+};
+
+// Alignment
+export const alignmentAPI = {
+  get: () =>
+    apiClient.get<AlignmentData>("/api/alignment").then((r) => r.data),
 };