fix(poker): idempotent hand logging + straddle capture

Two issues from live testing:

- Double-logged hand. The chat turn can execute TWICE — the SSE stream and the
  blocking fallback both run server-side (two 'chat request' lines, 1s apart) — a
  pre-existing double-execution (it also duplicated user messages) that the new
  logging guarantee turned into duplicate HANDS. record_hand is now idempotent:
  _recent_duplicate_hand returns an identical hand (same session, hole cards, board;
  NULL-safe) recorded in the last few minutes, so the second run reuses it instead
  of inserting. A system-of-record records an event once.

- Button straddle dropped. The parse prompt had no straddle logic. Added a STRADDLES
  rule: record any straddle as a preflop `post` by the straddler with its amount and
  respect the action order (button straddle acts last preflop, action opens in the
  SB; UTG straddle opens to its left). Verified: a btn-straddle hand now parses the
  straddle as {pos: BTN, action: post, amount: 6}.

Note: the underlying double turn-execution (stream + fallback) is a separate web-layer
bug worth fixing at the source — it wastes a full LLM turn and still double-persists
chat messages. Filed for a follow-up. 6 tests; suite 223 green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_hand_dedup.py

@@ -0,0 +1,67 @@
+"""record_hand idempotency + straddle parse coverage.
+
+The chat turn can execute twice — the SSE stream and the blocking fallback both run
+server-side (two 'chat request' lines, 1s apart) — which double-logged the same hand
+once logging became guaranteed. A system-of-record must record an event once."""
+from __future__ import annotations
+
+import importlib
+
+import pytest
+
+
+@pytest.fixture
+def poker(tmp_path, monkeypatch):
+    monkeypatch.setenv("LYRA_DB_PATH", str(tmp_path / "test.db"))
+    from lyra import llm
+    monkeypatch.setattr(llm, "embed", lambda texts: [[0.1, 0.2, 0.3] for _ in texts])
+    import lyra.memory as memory
+    importlib.reload(memory)
+    import lyra.poker as poker
+    importlib.reload(poker)
+    return poker
+
+
+_PARSED = {
+    "game": "NLH", "hero_pos": "SB", "hero_cards": ["Ah", "Kh"],
+    "board": ["Kd", "9d", "4c", "2s"], "players": [], "actions": [],
+    "result": {"hero_net": -200, "pot": 400},
+}
+
+
+def test_record_hand_is_idempotent_across_double_execution(poker, monkeypatch):
+    sid = poker.start_session(venue="Borgata", stakes="1/3", buy_in=400)
+    monkeypatch.setattr(poker, "parse_hand", lambda *a, **k: dict(_PARSED))
+    first = poker.record_hand("i have AhKh in the SB, btn straddle, ...")
+    second = poker.record_hand("i have AhKh in the SB, btn straddle, ...")   # the duplicate turn
+    assert first["id"] == second["id"]
+    assert second.get("deduped") is True
+    assert len(poker.list_hands(sid)) == 1          # ledger holds ONE, not two
+
+
+def test_record_hand_does_not_dedupe_a_genuinely_different_hand(poker, monkeypatch):
+    sid = poker.start_session(venue="Borgata", stakes="1/3", buy_in=400)
+    monkeypatch.setattr(poker, "parse_hand", lambda *a, **k: dict(_PARSED))
+    poker.record_hand("hand one")
+    other = dict(_PARSED, hero_cards=["Qs", "Qd"], board=["Qh", "7c", "2s"])
+    monkeypatch.setattr(poker, "parse_hand", lambda *a, **k: dict(other))
+    poker.record_hand("a different hand entirely")
+    assert len(poker.list_hands(sid)) == 2          # distinct hands both land
+
+
+def test_dedupe_handles_boardless_hand(poker, monkeypatch):
+    # NULL-safe match: a preflop-only hand (no board) still dedupes.
+    sid = poker.start_session(venue="Borgata", buy_in=400)
+    preflop = {"game": "NLH", "hero_pos": "BTN", "hero_cards": ["As", "Ks"],
+               "board": [], "players": [], "actions": [], "result": {"hero_net": 30}}
+    monkeypatch.setattr(poker, "parse_hand", lambda *a, **k: dict(preflop))
+    a = poker.record_hand("AKs btn, i open everyone folds")
+    b = poker.record_hand("AKs btn, i open everyone folds")
+    assert a["id"] == b["id"] and len(poker.list_hands(sid)) == 1
+
+
+def test_parse_prompt_records_straddles():
+    from lyra import poker as pk
+    p = pk._HAND_PARSE_PROMPT.lower()
+    assert "straddle" in p and "button straddle" in p
+    assert "acts last preflop" in p or "act last preflop" in p