Add a Monday-morning weekly recap briefing

No US session closes into Monday KST, so Mondays (default 07:00, cron
in the daemon with restart catch-up) now publish a weekly review built
entirely from stored data: the quotes table collapsed into week-over-
week changes and the week's daily briefing headlines as the narrative.
The recap is a BriefingResult kind="weekly" reusing MarketPayload, so
the store, verification pass, all delivery channels (Blogger title
"미국 주간 리뷰 <monday>") and the dashboard (주간 리뷰 badge) work
unchanged. Manual runs via `run-once --weekly [--date <monday>]`.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_blogger.py

@@ -255,3 +255,11 @@ def test_build_deliverers_includes_blogger_when_configured(tmp_path):
     blogger = deliverers[-1]
     assert blogger.labels == ["미국증시", "시황"]  # type: ignore[attr-defined]
     assert blogger.blog_id == "1"  # type: ignore[attr-defined]
+
+
+def test_post_title_weekly_kind():
+    result = make_result()
+    result = result.model_copy(update={"kind": "weekly"})
+    assert post_title(result) == "미국 주간 리뷰 2026-09-01 — 9월 첫 거래일 하락"
+    degraded = make_result(headline=None).model_copy(update={"kind": "weekly"})
+    assert post_title(degraded).startswith("미국 주간 리뷰 2026-09-01 (미 ")