fix-chartlab-findings (ornith-35): real OHLC candlesticks (CandleShape), remove dead CandleBar, rsiCaption figcaption, relvol domain

Re-review by qwopus35b pending. SPA lint 2/2 green.

app/src/components/ChartLabPanel.tsx

@@ -8,6 +8,7 @@ import {
   BarChart,
   CartesianGrid,
   Cell,
+  Defs,
   Legend,
   Line,
   LineChart,
@@ -157,14 +158,40 @@ export function ChartLabPanel() {
   const upColor = DAY_COLORS.up;
   const downColor = DAY_COLORS.down;
 
-  // Build a custom bar fill that respects up/down.
-  const CandleBar = (props: any) => {
+  // Custom shape for OHLC candlestick rendering: wick (high→low line) + body (open↔close rectangle).
+  const CandleShape = (props: any) => {
     const { x, y, width, height, payload } = props;
-    const fill = payload.c >= payload.o ? upColor : downColor;
+    if (!payload) return null;
+    const isUp = payload.c >= payload.o;
+    const fill = isUp ? upColor : downColor;
+    const bodyTop = Math.min(payload.o, payload.c);
+    const bodyBottom = Math.max(payload.o, payload.c);
+    const bodyHeight = Math.max(bodyBottom - bodyTop, 1); // minimum 1px body
+    const wickTop = payload.h;
+    const wickBottom = payload.l;
+
     return (
-      <Bar dataKey="range" {...props}>
-        <Cell fill={fill} opacity={0.35} />
-      </Bar>
+      <g>
+        {/* Wick: vertical line from high to low */}
+        <line
+          x1={x + width / 2}
+          y1={wickTop}
+          x2={x + width / 2}
+          y2={wickBottom}
+          stroke={fill}
+          strokeWidth={1}
+        />
+        {/* Body: rectangle from open to close */}
+        <rect
+          x={x + 1}
+          y={bodyTop}
+          width={Math.max(width - 2, 1)}
+          height={bodyHeight}
+          fill={isUp ? fill : fill}
+          stroke={fill}
+          strokeWidth={0.5}
+        />
+      </g>
     );
   };
 
@@ -178,14 +205,14 @@ export function ChartLabPanel() {
           <p className="text-xs text-[#5a5b6a] mb-2">{UI_STRINGS.priceChartCaption}</p>
           <div className="h-72">
             <ResponsiveContainer width="100%" height="100%">
-              <LineChart data={chartData} margin={{ top: 8, right: 8, bottom: 8, left: 8 }}>
+              <BarChart data={chartData} margin={{ top: 8, right: 8, bottom: 8, left: 8 }}>
                 <CartesianGrid strokeDasharray="3 3" stroke="#2a2b3a" />
                 <XAxis dataKey="date" tick={{ fontSize: 10, fill: "#5a5b6a" }} interval="preserveStartEnd" />
                 <YAxis domain={["auto", "auto"]} tick={{ fontSize: 10, fill: "#5a5b6a" }} />
                 <Tooltip
                   labelFormatter={(label) => `Date: ${label}`}
                   formatter={(value: any, name: string) => {
-                    if (name === "close") return [`$${value?.toFixed(2)}`, UI_STRINGS.priceLabel];
+                    if (name === "candle") return [`$${value?.toFixed(2)}`, UI_STRINGS.priceLabel];
                     if (name.startsWith("ema")) {
                       const period = name.replace("ema", "");
                       return [`$${value?.toFixed(2)}`, `${UI_STRINGS[`ema${period}Label` as keyof typeof UI_STRINGS] ?? `EMA ${period}`}`];
@@ -201,6 +228,12 @@ export function ChartLabPanel() {
                     return `${UI_STRINGS[`ema${period}Label` as keyof typeof UI_STRINGS] ?? `EMA ${period}`}`;
                   }}
                 />
+                <Bar
+                  dataKey="c"
+                  shape={<CandleShape />}
+                  name="candle"
+                  opacity={0.85}
+                />
                 <Line
                   type="monotone"
                   dataKey="c"
@@ -208,6 +241,7 @@ export function ChartLabPanel() {
                   strokeWidth={1.5}
                   dot={false}
                   name="close"
+                  strokeOpacity={0.6}
                 />
                 {Object.entries(EMA_COLORS).map(([period, color]) => (
                   <Line
@@ -220,7 +254,7 @@ export function ChartLabPanel() {
                     name={`ema${period}`}
                   />
                 ))}
-              </LineChart>
+              </BarChart>
             </ResponsiveContainer>
           </div>
           <figcaption className="text-[11px] text-[#5a5b6a] mt-1">
@@ -280,7 +314,7 @@ export function ChartLabPanel() {
             </ResponsiveContainer>
           </div>
           <figcaption className="text-[11px] text-[#5a5b6a] mt-1">
-            {UI_STRINGS.rsiTooltip}
+            {UI_STRINGS.rsiCaption}
           </figcaption>
         </figure>
       </div>
@@ -294,7 +328,7 @@ export function ChartLabPanel() {
               <BarChart data={chartData}>
                 <CartesianGrid strokeDasharray="3 3" stroke="#2a2b3a" />
                 <XAxis dataKey="date" tick={{ fontSize: 10, fill: "#5a5b6a" }} interval="preserveStartEnd" hide />
-                <YAxis tick={{ fontSize: 10, fill: "#5a5b6a" }} />
+                <YAxis domain={[0, "dataMax"]} tick={{ fontSize: 10, fill: "#5a5b6a" }} />
                 <Tooltip
                   formatter={(value: number) => {
                     const label = value > 1 ? "above typical" : value < 1 ? "below typical" : "at typical";