Population gate: trade only real gappers — the year-long +EV boundary

The gapper-history reconstruction (n=3,008 symbol-days / 14 months) REFUTED the 15-min
confirmation gate (late crosses beat early 12/14 months incl June 2026 — the 19-day
"+0.42R early" was a definition artifact) and found the first at-scale +EV configuration:
top-20 ranked gappers (gap >= 10%, $1-20, day volume >= 300k) are +0.05..+0.15R under the
live BE@+5% ratchet exits in EVERY rank x timing segment — including rank 6-20 ("D tier",
owner-approved: +0.153R early, the best cell). The live book bled by trading OUTSIDE that
population (low-gap, thin names), not by mistiming.

- ExecutionSettings.min_entry_gap_pct / min_day_volume (TRADING_MIN_ENTRY_GAP_PCT=0.10,
  TRADING_MIN_DAY_VOLUME=300000): POPULATION gate on BOTH entry paths — auto path skips +
  logs rule_type=population_below; fast path returns skipped=population_below. Fail-open
  on missing data (house rule: never block on unknowns).
- evaluate_setup now surfaces the true overnight gap_pct in signal_data; ready-signal
  snapshot passes it through.
- fast path: submit_breakout_now takes gap_pct (trigger book stores % units; call site
  normalizes to fraction); TRIGGER_GAP_MIN raised 3 -> 10 to align the arm floor.
- confirmation gate flipped OFF via env (code stays, 0=disabled).
- rank concentration stays OFF (owner call, data-consistent: rank 6-20 converts fine).

Tests: population skip+log, real gapper passes, fail-open on missing data. 52 pass.
Monday config: population gate + cap 10 fills + quality C+ + VWAP + BE@+5% ratchet + SIP.

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

run_live_paper.py

@@ -862,6 +862,7 @@ def main(argv: list[str] | None = None) -> int:
                     t.symbol, t.trigger, t.stop, last_price=t.price,
                     cum_volume=t.cum_volume, halted=_recently_halted(t.symbol),
                     day_open=t.day_open, rank=t.rank,
+                    gap_pct=(t.gap_pct / 100.0) if t.gap_pct else None,  # book stores % units
                 )
                 if res.get("ok"):
                     book.mark_fired(t.symbol)