feat: Equity/Avail funds tile in dashboard P&L strip

Shows total_equity and buying_power (settled available cash) from the
latest account snapshot. On the Tradier live cash account these diverge
for days after a deposit or sale (T+1) — the bot sizes off equity but
buys need settled cash, so the gap explains rejected entries at a glance.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

api/static/dashboard.html

@@ -498,6 +498,7 @@
   <div class="pnl-cell"><div class="label">Win Rate</div><div class="value num" id="pnl-winrate">—</div></div>
   <div class="pnl-cell"><div class="label">Avg R</div><div class="value num" id="pnl-avgr">—</div></div>
   <div class="pnl-cell"><div class="label">Open / Closed</div><div class="value num" id="pnl-counts">—</div></div>
+  <div class="pnl-cell"><div class="label">Equity / Avail</div><div class="value num" id="pnl-funds">—</div></div>
   <div class="pnl-cell pnl-spark"><div class="label">Day Curve</div><div id="equity-spark" class="eqspark">—</div></div>
 </div>
 
@@ -1450,6 +1451,15 @@ function render(d) {
   $("pnl-avgr").className = "value num " + (p.avg_r_multiple > 0 ? "pos" : p.avg_r_multiple < 0 ? "neg" : "");
   $("pnl-counts").textContent = (p.open_positions != null ? p.open_positions : 0) + " / " + (p.closed_trades != null ? p.closed_trades : 0);
   $("pnl-counts").className = "value num";
+  // equity + settled/available funds (cash account: buys need settled cash,
+  // so available can lag equity by days after a deposit or sale)
+  if (acct0.account_id) {
+    const eq = acct0.total_equity != null ? acct0.total_equity : acct0.net_liquidating_value;
+    const avail = acct0.buying_power;
+    $("pnl-funds").textContent = money(eq) + " / " + (avail != null ? money(avail) : "—");
+  } else {
+    $("pnl-funds").textContent = "—";
+  }
 
   // portfolio risk strip + naked-position alarm — the conditions that silently
   // cost money this session, now visible.