fix: render flat-logged hands + on-demand "build replay"

Quick-logged hands (log_hand) store flat fields with no structured JSON, so the
hand viewer dead-ended with "no structured data to replay" — even when the full
street-by-street action was captured (e.g. the KhQh-vs-Louis hand). Now:

- hand.html renders a readable STATIC view of any flat hand (hero cards, board,
  street narratives, result, lesson) instead of erroring; also handles empty/garbage
  structured rows by falling back to the flat view.
- "▶ Build replay" button + poker.reconstruct_hand + POST /hand/{id}/reconstruct:
  parse a flat hand's narrative into structured form on demand, making any
  quick-logged hand replayable without an LLM call per log during live play.
- test_modes.py +1 (reconstruct wiring).

(Also reconstructed the two live Meadows hands and removed one empty hand in the DB.)

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

tests/test_modes.py

@@ -175,6 +175,24 @@ def test_session_state_readback(lyra):
     assert "great river fold" in out
 
 
+def test_reconstruct_flat_hand(lyra, monkeypatch):
+    _, poker, _, _ = lyra
+    poker.start_session(stakes="1/3", buy_in=300)
+    hid = poker.log_hand(position="UTG", hole_cards="KhQh",
+                         preflop="UTG raises, BTN calls", flop="Qd Qs Jc, bet, call",
+                         river="Kd, all in, called", showdown="hero wins", result=225)
+    assert poker.get_hand(hid)["structured"] is None  # flat (log_hand) — not replayable yet
+    monkeypatch.setattr(poker, "parse_hand", lambda *a, **k: {
+        "hero_pos": "UTG", "hero_cards": ["Kh", "Qh"],
+        "players": [{"pos": "UTG"}],
+        "actions": [{"street": "preflop", "pos": "UTG", "action": "raise"}],
+        "board": ["Qd", "Qs", "Jc", "6d", "Kd"]})
+    out = poker.reconstruct_hand(hid)
+    assert out is not None
+    h = poker.get_hand(hid)
+    assert h["structured"]["hero_pos"] == "UTG" and len(h["structured"]["actions"]) == 1
+
+
 def test_undo_last_and_delete_entry(lyra):
     _, poker, modes, tools = lyra
     assert "undo_last" in modes.CASH.tools