feat(members): add full member bio, contact info, and service history

Lazy-enriches member profiles on first view via Congress.gov detail API.
Adds office address, phone, official website, congress.gov link, birth
year, terms history, leadership roles, and sponsored/cosponsored counts.
Includes DB migration 0007 for new member columns.

Co-Authored-By: Jack Levy

frontend/lib/types.ts

@@ -1,3 +1,20 @@
+export interface MemberTerm {
+  congress?: number;
+  chamber?: string;
+  partyName?: string;
+  stateCode?: string;
+  stateName?: string;
+  startYear?: number;
+  endYear?: number;
+  district?: number;
+}
+
+export interface MemberLeadership {
+  type?: string;
+  congress?: number;
+  current?: boolean;
+}
+
 export interface Member {
   bioguide_id: string;
   name: string;
@@ -8,6 +25,15 @@ export interface Member {
   chamber?: string;
   district?: string;
   photo_url?: string;
+  official_url?: string;
+  congress_url?: string;
+  birth_year?: string;
+  address?: string;
+  phone?: string;
+  terms_json?: MemberTerm[];
+  leadership_json?: MemberLeadership[];
+  sponsored_count?: number;
+  cosponsored_count?: number;
 }
 
 export interface CitedPoint {