Small joys backend: shared daily framework + On This Day engine

- goodnews/daily.py: shared helpers for the daily "small joys" (http_json, date-seeded
  deterministic pick, dedup key) so each joy is a small self-contained module.
- goodnews/onthisday.py: harvest today's MM-DD from Wikimedia's On-this-day feed →
  tone-filter to good/neutral (keyword floor + optional LLM refine) → pool → deterministic
  daily pick (idempotent, respects blocked/featured) → cached row. Network/LLM before any
  DB write. Multi-source ready (source column).
- db.py: onthisday_pool + daily_onthisday tables.
- api.py: GET /api/onthisday/today (edge-cacheable).
- cli.py: cycle step (run after Daily Art; --no-joys to skip), LLM client for tone refine.
- tests/test_onthisday.py: 7 tests (filter+dedup, pick idempotent, blocked/featured,
  never-empty, empty-pool, LLM-narrow). 382 backend tests green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

goodnews/cli.py

@@ -13,7 +13,7 @@ from .games import generate_daily_puzzles
 from .localtime import local_today
 from .dedup import DEFAULT_THRESHOLD, DEFAULT_WINDOW_DAYS, cluster_duplicates, dedup as run_dedup
 from .geo import tag_articles as tag_geo
-from . import art
+from . import art, onthisday
 from .enrich import enrich_brief_images, enrich_recent_images, enrich_summarized_images
 from .summarize import generate_summary, get_summary
 from .feeds import (
@@ -137,6 +137,7 @@ def main() -> None:
     cycle_parser.add_argument("--no-geo", action="store_true", help="Skip tagging article subject-geography")
     cycle_parser.add_argument("--geo-limit", type=int, default=60, help="Max articles to geo-tag per cycle")
     cycle_parser.add_argument("--no-art", action="store_true", help="Skip the Daily Art pick")
+    cycle_parser.add_argument("--no-joys", action="store_true", help="Skip the small-joys picks (On This Day, etc.)")
     cycle_parser.add_argument("--no-brief", action="store_true", help="Skip rebuilding today's brief")
     cycle_parser.add_argument("--no-review", action="store_true", help="Skip recomputing source review flags")
     cycle_parser.add_argument("--no-digest", action="store_true", help="Skip sending due daily digests")
@@ -560,6 +561,14 @@ def _run_cycle_locked(conn: sqlite3.Connection, args: argparse.Namespace) -> Non
         except Exception as exc:
             print(f"art: skipped ({exc})")
 
+    # On This Day: harvest + tone-filter today's date in history, then pick one good fact.
+    if not args.no_joys:
+        try:
+            o = onthisday.run_daily(conn, client=LocalModelClient.from_env())
+            print(f"onthisday: md={o['md']} picked={'yes' if o['picked'] else 'no'}")
+        except Exception as exc:
+            print(f"onthisday: skipped ({exc})")
+
     if not args.no_brief:
         today = local_today()
         try: