Sparse-day-proof briefs, feed health check, and 16 new sources

- Briefs now fill from a rolling window (prefer today, backfill up to
  window_days) and exclude anything featured in the last 7 days of briefs, so
  slow days still produce five items without stories lingering day to day.
- New 'check-feeds' command fetches and parses every feed to catch dead ones.
- Added 16 validated sources (science, environment, animals, culture),
  expanding coverage from 12 to 28 feeds to reduce staleness.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

goodnews/cli.py

@@ -8,7 +8,7 @@ from pathlib import Path
 
 from .briefs import build_daily_brief, show_brief
 from .db import connect, init_db
-from .feeds import poll_all_sources, poll_due_sources, poll_source
+from .feeds import fetch_feed, parse_feed, poll_all_sources, poll_due_sources, poll_source
 from .llm import LocalModelClient, classify_articles
 from .scoring import score_article
 from .sources import load_sources, upsert_sources
@@ -48,6 +48,9 @@ def main() -> None:
 
     subparsers.add_parser("source-report", help="Show source-level ingestion and scoring stats")
 
+    check_feeds_parser = subparsers.add_parser("check-feeds", help="Fetch and parse each feed, reporting health")
+    check_feeds_parser.add_argument("--all", action="store_true", help="Include inactive sources")
+
     runs_parser = subparsers.add_parser("list-runs", help="Show recent ingest runs")
     runs_parser.add_argument("--limit", type=int, default=20)
 
@@ -122,6 +125,8 @@ def main() -> None:
         list_category(conn, topic=args.topic, flavor=args.flavor, limit=args.limit, accepted_only=not args.all)
     elif args.command == "source-report":
         source_report(conn)
+    elif args.command == "check-feeds":
+        check_feeds(conn, include_inactive=args.all)
     elif args.command == "list-runs":
         list_runs(conn, limit=args.limit)
     elif args.command == "rescore":
@@ -214,6 +219,20 @@ def list_recent(conn: sqlite3.Connection, limit: int, accepted_only: bool) -> No
         print(f"  {row['canonical_url']}")
 
 
+def check_feeds(conn: sqlite3.Connection, include_inactive: bool = False) -> None:
+    where = "" if include_inactive else "WHERE active = 1"
+    rows = conn.execute(f"SELECT name, feed_url FROM sources {where} ORDER BY name").fetchall()
+    ok = 0
+    for row in rows:
+        try:
+            items = parse_feed(fetch_feed(row["feed_url"]))
+            ok += 1
+            print(f"OK   {row['name']}: {len(items)} items")
+        except Exception as exc:
+            print(f"FAIL {row['name']}: {exc}")
+    print(f"--- {ok}/{len(rows)} feeds healthy ---")
+
+
 def run_cycle(conn: sqlite3.Connection, args: argparse.Namespace) -> None:
     """One end-to-end pass for a scheduler: poll due sources, classify the new
     arrivals, rebuild today's brief. Each step is independent and non-fatal so a