population: learn_params + eod_replay consume the shared gate (kills look-ahead)

Both offline consumers now screen through strategy.population.population_reject
instead of divergent, look-ahead admits:

- learn_params.load_sessions: replaces the `gap>=0.03 OR day_rvol>=2.0` admit,
  whose day_rvol was a FULL-DAY volume sum (outcome-time look-ahead, the
  2026-07-08 class). gap is already a FRACTION (open vs prev close) — passed
  as-is; the OPEN price is passed for the price band. Stored daily bars expose
  no open-knowable volume, so volume=None (fail-open on the day-volume floor) —
  no day-end volume is smuggled into admission.
- eod_replay._daily_gappers: screens on the OPEN price + STATIC open gap (was
  t_close look-ahead) via the shared gate; the local gap is converted to a
  FRACTION before the call, so it inherits the >=150% squeeze exception. Deletes
  the stale $1-5 / 3-60% WATCHER_/TRIGGER_ constants (KEEPS RISK_PCT). The
  second-stage scan_gappers is made permissive (membership already decided by
  the shared gate), removing the `gap_pct <= 60%` cap that wrongly dropped
  squeezes. Prod thresholds passed explicitly (bare from_env would disable gap).

Unit test replaces the live-DB smoke run: $15/+12% qualifies, $4/+45% rejected
unless >=150%+rvol5. research/labeler.py deferred to plan 006 (no locatable
price/gap admission screen); sweep_exits/sweep_filters likewise deferred.

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

tests/unit/test_eod_replay_population.py

@@ -0,0 +1,55 @@
+"""Unit test standing in for the `python eod_replay.py <date>` smoke verify
+(the live DB must never be touched). Pins that eod_replay._daily_gappers now
+screens through the shared population gate on the OPEN price + STATIC open gap,
+inheriting the >=150% squeeze exception and dropping the old $1-5 / 3-60% /
+t_close look-ahead screen.
+
+Verify (plan step 3): a $15 name with a 12% open gap qualifies; a $4 name with a
+45% gap does not unless >=150% + rvol>=5.
+"""
+
+from datetime import date
+
+import eod_replay
+
+SESS = date(2026, 7, 10)
+PRIOR = date(2026, 7, 9)
+
+
+def _rows(open_px, prev_close, day_vol=1000.0, prior_vol=1000.0):
+    """daily_bars rows newest-first: (trade_date, open, close, volume).
+    row[0] = session day, row[1..] = prior days (for prev_close + 20-day adv)."""
+    day = (SESS, open_px, open_px, day_vol)
+    prior = [(PRIOR, prev_close, prev_close, prior_vol) for _ in range(20)]
+    return [day] + prior
+
+
+class _Result:
+    def __init__(self, rows):
+        self._rows = rows
+
+    def fetchall(self):
+        return self._rows
+
+
+class _FakeCon:
+    def __init__(self, by_sym):
+        self.by_sym = by_sym
+
+    def execute(self, sql, params):  # params == [symbol, session_date]
+        return _Result(self.by_sym.get(params[0], []))
+
+
+def test_daily_gappers_uses_shared_population_gate():
+    by_sym = {
+        # open price, prev_close chosen so open/prev_close - 1 == target gap
+        "BIG15": _rows(15.0, 15.0 / 1.12),                       # $15, +12% -> IN
+        "DEAD4": _rows(4.0, 4.0 / 1.45),                         # $4, +45% dead band -> OUT
+        "SQZ6": _rows(4.0, 4.0 / 3.0, day_vol=6000, prior_vol=1000),  # +200% rvol6 -> IN
+        "SQZ2": _rows(4.0, 4.0 / 3.0, day_vol=2000, prior_vol=1000),  # +200% rvol2 -> OUT
+        "CHEAP": _rows(0.98, 0.98 / 1.20),                      # $0.98 below band -> OUT
+        "LOWGAP": _rows(10.0, 10.0 / 1.05),                     # +5% below floor -> OUT
+    }
+    con = _FakeCon(by_sym)
+    keep = eod_replay._daily_gappers(con, SESS, list(by_sym))
+    assert set(keep) == {"BIG15", "SQZ6"}