market-aware AI cadence + incremental log updates

Two changes that together cut OpenRouter spend ~50% and give the daily
log temporal awareness.

1. CadencePolicy (app/services/cadence.py): expensive AI jobs only
   fire hourly during the EU/US active window (Mon-Fri 07-21 UTC).
   Off-hours weekdays throttle to every 4h; weekends to every 12h.
   ai_log_job and indicator_summary_job both consult the policy before
   doing real work; market/news/portfolio ingest jobs stay hourly
   (cheap, no API cost). Skipped runs land in job_runs with status
   'skipped' and the throttle reason in error.

2. Update mode for ai_log_job: when an earlier log exists for the
   current UTC day, it's passed to the model as 'Earlier log from
   today (generated HH:MM UTC)'. The system prompt grows an Update
   mode section instructing the model to revise — not restart — and
   anchor on what has CHANGED since the earlier draft. The TL;DR
   leads with intra-day change when meaningful, the watch list evolves
   rather than restarts. PROMPT_VERSION bumped to 5.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/jobs/indicator_summary_job.py

@@ -13,7 +13,8 @@ from sqlalchemy import desc, func, select
 from app.config import get_settings, load_groups
 from app.db import utcnow
 from app.jobs._helpers import job_lifecycle, log
-from app.models import AICall, IndicatorSummary, Quote
+from app.models import AICall, IndicatorSummary, JobRun, Quote
+from app.services.cadence import DEFAULT_POLICY
 from app.services.openrouter import (
     PROMPT_VERSION,
     build_aggregate_summary_system_prompt,
@@ -234,6 +235,21 @@ async def run() -> None:
             jr.status = "skipped"
             return
 
+        # Cadence — same policy as ai_log_job: hourly during EU/US active,
+        # throttled off-hours and weekends.
+        last_success = (await session.execute(
+            select(func.max(JobRun.finished_at)).where(
+                JobRun.name == "indicator_summary_job",
+                JobRun.status == "success",
+            )
+        )).scalar()
+        should_run, reason = DEFAULT_POLICY.should_run(last_success)
+        if not should_run:
+            log.info("ind_summary.cadence_skip", reason=reason)
+            jr.status = "skipped"
+            jr.error = reason
+            return
+
         spent = await _month_spend(session)
         if spent >= s.OPENROUTER_MONTHLY_CAP_USD:
             jr.status = "skipped"