chore: remove dead functions and write-only state (no behaviour change)

Zero callers anywhere (tests included), verified by grep/AST:
- dashboard_publisher.DashboardPublisher.publish_all (run_cycle inlines both publishes)
- signal_log.SignalLogger.advance_with_bars (the backfill script uses
  backfill_seeds / resolve_from_store / reseed_unresolvable) and the never-read
  SignalLogger.path property plus its write-only self._path
- llm_client.reset_llm_client (tests reset the singleton by assignment)
- market_outlook._last_run_ts, residue of the old "now - last < 3600" dedup;
  _last_run_hour (the UTC hour bucket) is the live key
- news_engine FundamentalContext.event_impact_on_pairs: written once, read by
  nothing; its only feeder NewsEngine._get_affected_pairs and that helper's
  unit test go with it
- position_sizing.LIVE_DEPTH_BARS (referenced only by its own docstring, which
  now states the depths inline), the unused Iterable import and the unused
  atr_ok parameter of _fill_geometry
- analyze_signal_log: unused `field` import and the unused `rows` parameter of
  persona_scorecard / news_outcome_buckets (both read the DB directly)

The two backfill/label scripts' --db help text now names the config.json
setting it actually falls back to.

Suite: 463 passed, 0 failed (one test removed with its subject).

Claude-Session: https://claude.ai/code/session_0156YhogLytzj9P2iH1skGbL

market_outlook.py

@@ -329,7 +329,6 @@ def _collect_payload(settings: Dict[str, Any]) -> Dict[str, Any]:
 # ── Orchestration, hourly dedup, and request budget ──────────────────
 
 _state_lock = threading.Lock()
-_last_run_ts: Optional[float] = None
 _last_run_hour: Optional[int] = None   # UTC hour bucket of the last attempt
 _outlook_day: Optional[_dt.date] = None
 _outlook_count = 0
@@ -344,10 +343,9 @@ def _skip(reason: str) -> None:
 
 def reset_outlook_state() -> None:
     """Drop hourly and daily state (tests / deployment config reloads)."""
-    global _last_run_ts, _last_run_hour, _outlook_day, _outlook_count
+    global _last_run_hour, _outlook_day, _outlook_count
     global _warned_budget
     with _state_lock:
-        _last_run_ts = None
         _last_run_hour = None
         _outlook_day = None
         _outlook_count = 0
@@ -360,7 +358,7 @@ def _begin_attempt(cap: int, force: bool) -> bool:
     Hourly dedup is by UTC hour BUCKET, not ``now - last < 3600``: the
     H1 loop calls this at boundary+10 s+scan time, so consecutive hours
     were routinely 3,590 s apart and every other hour was dropped."""
-    global _last_run_ts, _last_run_hour, _outlook_day, _outlook_count
+    global _last_run_hour, _outlook_day, _outlook_count
     global _warned_budget
     now = time.time()
     hour_bucket = int(now // 3600)
@@ -383,7 +381,6 @@ def _begin_attempt(cap: int, force: bool) -> bool:
                 _skip("daily budget exhausted")
             return False
         _outlook_count += 1
-        _last_run_ts = now
         _last_run_hour = hour_bucket
         return True