Add bill action pipeline, admin health panel, and LLM provider fixes

- Fetch bill actions from Congress.gov and populate the action timeline
- Add nightly batch task and beat schedule for active bill actions
- Add admin reprocess endpoint for per-bill debugging
- Add BriefPanel with "What Changed" view and version history
- Add External API Health section with per-source latency testing
- Redesign Manual Controls as health panel with status dots and descriptions
- Add Resume Analysis task for stalled LLM jobs
- Add Backfill Dates & Links task for bills with null metadata
- Fix LLM provider/model DB overrides being ignored (env vars used instead)
- Fix Gemini 404: gemini-1.5-pro deprecated → gemini-2.0-flash
- Fix Anthropic models list: use REST API directly (SDK too old for .models)
- Replace test-LLM full analysis with lightweight ping (max_tokens=20)
- Add has_document field to BillDetail; show "No bill text published" state
- Fix "Introduced: —" showing for bills with null introduced_date
- Add bills_missing_sponsor and bills_missing_metadata to admin stats
- Add GovInfo health check using /collections endpoint (fixes 500 from /packages)

Authored-By: Jack Levy

backend/app/api/bills.py

@@ -6,7 +6,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
 
 from app.database import get_db
-from app.models import Bill, BillAction, BillBrief, NewsArticle, TrendScore
+from app.models import Bill, BillAction, BillBrief, BillDocument, NewsArticle, TrendScore
 from app.schemas.schemas import (
     BillDetailSchema,
     BillSchema,
@@ -109,6 +109,10 @@ async def get_bill(bill_id: str, db: AsyncSession = Depends(get_db)):
         detail.latest_brief = bill.briefs[0]
     if bill.trend_scores:
         detail.latest_trend = bill.trend_scores[0]
+    doc_exists = await db.scalar(
+        select(func.count()).select_from(BillDocument).where(BillDocument.bill_id == bill_id)
+    )
+    detail.has_document = bool(doc_exists)
 
     # Trigger a background news refresh if no articles are stored but trend
     # data shows there are gnews results out there waiting to be fetched.