feat: undo / delete logged entries (fix fat-fingered live logging)

Previously the only delete was whole-session, so a mis-logged stack or a
mis-parsed hand was stuck on the HUD. Now:

- undo_last tool ("scratch that") — deletes the most recent hand/stack/read/
  scar/confidence/reset in the live session; added to the Cash toolset.
- poker.delete_hand/stack/read/ritual + delete_entry dispatch + undo_last.
- DELETE /session/entry/{kind}/{id} endpoint.
- HUD: per-row × delete buttons on hands, confidence-bank, and scar-note rows
  (stack/read deletes via the tool). Row ids now surfaced in the hud() bundle.
- test_modes.py +2 (undo_last across kinds, tool handler); 46 green.

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

tests/test_modes.py

@@ -175,6 +175,46 @@ def test_session_state_readback(lyra):
     assert "great river fold" in out
 
 
+def test_undo_last_and_delete_entry(lyra):
+    _, poker, modes, tools = lyra
+    assert "undo_last" in modes.CASH.tools
+    poker.start_session(venue="Meadows", stakes="2/5", buy_in=500)
+    h1 = poker.log_hand(position="UTG", hole_cards="AA")
+    h2 = poker.log_hand(position="BTN", hole_cards="72o")
+    poker.log_stack(600); poker.log_stack(420)
+    poker.log_ritual("scar", content="punted")
+    poker.log_ritual("confidence", content="good fold")
+
+    # undo removes the most recent of each kind
+    assert "72o" in poker.undo_last("hand")
+    assert [h["hole_cards"] for h in poker.list_hands()] == ["AA"]  # h2 gone, h1 stays
+    assert "420" in poker.undo_last("stack")
+    assert poker.current_stack() == 600
+    assert "punted" in poker.undo_last("scar")
+    assert not poker.list_rituals(kinds=("scar",))
+    assert poker.list_rituals(kinds=("confidence",))  # untouched
+    assert poker.undo_last("hand") is not None  # h1
+    assert poker.undo_last("hand") is None       # nothing left
+
+    # direct delete-by-id dispatch
+    assert poker.delete_entry("ritual", poker.list_rituals(kinds=("confidence",))[0]["id"]) is True
+    assert poker.delete_entry("bogus", 1) is False
+
+
+def test_undo_last_tool(lyra):
+    _, poker, _, tools = lyra
+    poker.start_session(stakes="1/3", buy_in=300)
+    poker.log_hand(position="CO", hole_cards="KK")
+    out = tools.dispatch("undo_last", {"what": "hand"}, {})
+    assert "scratched" in out.lower() and poker.list_hands() == []
+    # no live session -> graceful
+    poker.end_session(cash_out=300)
+    assert "no live session" in tools.dispatch("undo_last", {"what": "hand"}, {}).lower()
+    # nonsense target
+    poker.start_session(stakes="1/3", buy_in=100)
+    assert "one of" in tools.dispatch("undo_last", {"what": "banana"}, {}).lower()
+
+
 def test_list_and_delete_session(lyra):
     _, poker, _, tools = lyra
     keep = poker.start_session(venue="Meadows", stakes="1/3", buy_in=300)