feat(interest): add public interest tracking for members of Congress

Adds Google Trends, NewsAPI, and Google News RSS scoring for members,
mirroring the existing bill interest pipeline. Member profiles now show
a Public Interest chart (with signal breakdown) and a Related News panel.

Key changes:
- New member_trend_scores + member_news_articles tables (migration 0008)
- fetch_gnews_articles() added to news_service for unlimited RSS article storage
- Bill news fetcher now combines NewsAPI + Google News RSS (more coverage)
- New member_interest Celery worker with scheduled news + trend tasks
- GET /members/{id}/trend and /news API endpoints
- TrendChart redesigned with signal breakdown badges and bar+line combo chart
- NewsPanel accepts generic article shape (bills and members)

Co-Authored-By: Jack Levy

backend/app/schemas/schemas.py

@@ -35,6 +35,7 @@ class MemberSchema(BaseModel):
     leadership_json: Optional[list[Any]] = None
     sponsored_count: Optional[int] = None
     cosponsored_count: Optional[int] = None
+    latest_trend: Optional["MemberTrendScoreSchema"] = None
 
     model_config = {"from_attributes": True}
 
@@ -94,6 +95,27 @@ class TrendScoreSchema(BaseModel):
     model_config = {"from_attributes": True}
 
 
+class MemberTrendScoreSchema(BaseModel):
+    score_date: date
+    newsapi_count: int
+    gnews_count: int
+    gtrends_score: float
+    composite_score: float
+
+    model_config = {"from_attributes": True}
+
+
+class MemberNewsArticleSchema(BaseModel):
+    id: int
+    source: Optional[str] = None
+    headline: Optional[str] = None
+    url: Optional[str] = None
+    published_at: Optional[datetime] = None
+    relevance_score: Optional[float] = None
+
+    model_config = {"from_attributes": True}
+
+
 # ── Bill ──────────────────────────────────────────────────────────────────────
 
 class BillSchema(BaseModel):