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>

us2kr/llm/base.py

@@ -16,12 +16,24 @@ class LLMProvider(Protocol):
         """Return (validated Report, model id that produced it). Raise LLMError on total failure."""
         ...
 
-    def verify(self, payload: MarketPayload, report: Report) -> tuple[Verification, str]:
-        """Fact-check `report` against the payload. Raise LLMError on total failure."""
+    def summarize_weekly(self, payload: MarketPayload, week_sessions: list) -> tuple[Report, str]:
+        """Weekly recap over a payload whose quotes carry week-over-week changes."""
+        ...
+
+    def verify(
+        self, payload: MarketPayload, report: Report, data_message: str | None = None
+    ) -> tuple[Verification, str]:
+        """Fact-check `report` against the payload (or `data_message`). Raise LLMError on total failure."""
         ...
 
     def revise(
-        self, payload: MarketPayload, report: Report, issues: list[VerificationIssue]
+        self,
+        payload: MarketPayload,
+        report: Report,
+        issues: list[VerificationIssue],
+        *,
+        system_prompt: str | None = None,
+        data_message: str | None = None,
     ) -> tuple[Report, str]:
         """Return a corrected Report addressing `issues`. Raise LLMError on total failure."""
         ...