Add Casino demo section with a Texas Hold'em dealer's pot-splitting assistant

New /casino hub page (Texas Hold'em live, other table games marked coming
soon) and /casino/texasholdem: a drag-and-drop seating table with
auto-rotating blinds, per-seat chip/dollar contribution tracking, and a
side-pot resolution wizard that asks who won and who's next until every
dollar in the pot (including dead money from folds) is assigned.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_018CmAti1baCjidbJM2HeJfk

JoshHeaps.Net/wwwroot/js/casino/holdem/main.js

@@ -0,0 +1,70 @@
+(function () {
+    const state = HoldemState.load();
+
+    const hooks = {
+        save: s => HoldemState.save(s),
+        rerender: () => Render.renderAll(),
+    };
+
+    Render.mount(state, hooks);
+
+    document.getElementById("seatCountInput").addEventListener("change", e => {
+        HoldemState.resizeSeats(state, Number(e.target.value));
+        hooks.save(state);
+        Render.renderAll();
+    });
+
+    document.getElementById("directionSelect").addEventListener("change", e => {
+        state.direction = e.target.value;
+        hooks.save(state);
+        Render.renderSeats();
+    });
+
+    document.getElementById("basePotInput").addEventListener("input", e => {
+        state.basePotAmount = e.target.value === "" ? null : Number(e.target.value);
+        hooks.save(state);
+        Render.renderAll();
+    });
+
+    document.getElementById("tableNotes").addEventListener("input", e => {
+        state.notes = e.target.value;
+        hooks.save(state);
+    });
+
+    document.getElementById("addChipColorBtn").addEventListener("click", () => {
+        state.chipLegend.push({
+            id: HoldemState.makeId("chip"),
+            color: "#888888",
+            value: 1,
+        });
+        hooks.save(state);
+        Render.renderAll();
+    });
+
+    document.getElementById("nextHandBtn").addEventListener("click", () => {
+        if (!confirm("Start the next hand? This moves the button, clears cards and chip counts for every seat.")) return;
+        HoldemState.startNextHand(state);
+        hooks.save(state);
+        Render.renderAll();
+    });
+
+    document.getElementById("resetTableBtn").addEventListener("click", () => {
+        if (!confirm("Reset the whole table? This clears every seat, chip legend and note.")) return;
+        HoldemState.clear();
+        Object.assign(state, HoldemState.createDefault());
+        Render.mount(state, hooks);
+    });
+
+    document.getElementById("resolvePotBtn").addEventListener("click", () => {
+        PotWizard.open(state, () => {
+            HoldemState.startNextHand(state);
+            hooks.save(state);
+            Render.renderAll();
+        });
+    });
+
+    document.getElementById("closePotWizardBtn").addEventListener("click", () => PotWizard.close());
+    document.getElementById("potWizardOverlay").addEventListener("click", e => {
+        if (e.target.id === "potWizardOverlay") PotWizard.close();
+    });
+})();