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

backend/app/schemas/schemas.py

@@ -26,6 +26,15 @@ class MemberSchema(BaseModel):
     chamber: Optional[str] = None
     district: Optional[str] = None
     photo_url: Optional[str] = None
+    official_url: Optional[str] = None
+    congress_url: Optional[str] = None
+    birth_year: Optional[str] = None
+    address: Optional[str] = None
+    phone: Optional[str] = None
+    terms_json: Optional[list[Any]] = None
+    leadership_json: Optional[list[Any]] = None
+    sponsored_count: Optional[int] = None
+    cosponsored_count: Optional[int] = None
 
     model_config = {"from_attributes": True}