Track session standings so the dealer can settle up at the end of the night

The hand log answered "what happened in hand 12"; it couldn't answer "what
does Alice owe". Each resolved pot now records a per-seat ledger (what that
player put in, what they took down) alongside the payouts, and a Session
Standings panel sums it into one row per player — paid in, won, net, sorted
by who's up. The CSV export carries the same table, so one file covers both
the hand-by-hand trail and the cash-out numbers.

Keyed by seat id rather than name, so renaming or reseating a player doesn't
split their totals. Hands recorded before this change have no ledger and are
skipped rather than counted wrong.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015bnp7xKUPFFSpwkYNFaPgb

JoshHeaps.Net/wwwroot/css/casino/holdem.css

@@ -617,6 +617,63 @@ body {
     padding: 0.3rem 0.5rem;
 }
 
+#standingsTable {
+    max-height: 260px;
+    overflow-y: auto;
+}
+
+.standingsRow {
+    display: grid;
+    grid-template-columns: minmax(0, 1fr) auto auto auto;
+    gap: 0.5rem;
+    align-items: baseline;
+    padding: 0.3rem 0.1rem;
+    font-size: 0.78rem;
+    border-bottom: 1px solid #232323;
+}
+
+.standingsRow > span:not(:first-child) {
+    text-align: right;
+    font-variant-numeric: tabular-nums;
+    min-width: 4.5rem;
+}
+
+.standingsHeader {
+    color: #777;
+    font-size: 0.7rem;
+    letter-spacing: 0.04em;
+    text-transform: uppercase;
+    border-bottom-color: #3a3a3a;
+    position: sticky;
+    top: 0;
+    background: #1b1b1b;
+}
+
+.standingsName {
+    color: #eee;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.standingsIn,
+.standingsWon {
+    color: #999;
+}
+
+.standingsNet {
+    color: #bbb;
+    font-weight: 600;
+}
+
+.standingsNet.netUp {
+    color: #4ec97a;
+}
+
+.standingsNet.netDown {
+    color: #e07b7b;
+}
+
 #handHistoryList {
     display: flex;
     flex-direction: column;