feat: 详情页K线增加技术指标 MA/MACD/RSI/KDJ

- 新增 indicators.ts 指标计算库：SMA/EMA/MACD(12,26,9)/RSI(14)/KDJ(9,3,3)
- KLineChart 支持指标开关：MA(5/10/20/30) 主图叠加、MACD/RSI/KDJ 独立副图 pane
- 图表高度随指标 pane 数量动态增长（主图 300 + 每个副图 95），主图不被压缩
- 指标全部前端本地计算，无需后端

src/lib/indicators.ts

@@ -0,0 +1,139 @@
+/**
+ * 技术指标计算（纯函数，前端本地计算）
+ * 输入 K 线数组（时间升序），输出与输入等长、前段为 null 的指标序列。
+ */
+
+export interface KBar {
+  time: string;
+  open: number;
+  close: number;
+  high: number;
+  low: number;
+  volume: number;
+}
+
+export type Nums = (number | null)[];
+
+/** 简单移动平均 */
+export function sma(closes: number[], period: number): Nums {
+  const out: Nums = new Array(closes.length).fill(null);
+  let sum = 0;
+  for (let i = 0; i < closes.length; i++) {
+    sum += closes[i];
+    if (i >= period) sum -= closes[i - period];
+    if (i >= period - 1) out[i] = sum / period;
+  }
+  return out;
+}
+
+/** EMA（标准 MACD 用的指数平滑） */
+export function ema(values: number[], period: number): Nums {
+  const out: Nums = new Array(values.length).fill(null);
+  const k = 2 / (period + 1);
+  let prev: number | null = null;
+  for (let i = 0; i < values.length; i++) {
+    if (i === period - 1) {
+      // 首值取前 period 个的 SMA
+      let s = 0;
+      for (let j = 0; j < period; j++) s += values[j];
+      prev = s / period;
+      out[i] = prev;
+    } else if (prev !== null) {
+      prev = values[i] * k + prev * (1 - k);
+      out[i] = prev;
+    }
+  }
+  return out;
+}
+
+/** MACD(12,26,9)：返回 DIF、DEA、MACD 柱（柱 = (DIF-DEA)*2，国内口径） */
+export function macd(
+  closes: number[],
+  fast = 12,
+  slow = 26,
+  signal = 9,
+): { dif: Nums; dea: Nums; hist: Nums } {
+  const ef = ema(closes, fast);
+  const es = ema(closes, slow);
+  const dif: Nums = closes.map((_, i) =>
+    ef[i] != null && es[i] != null ? (ef[i] as number) - (es[i] as number) : null,
+  );
+  // DEA = DIF 的 9 日 EMA（跳过 null）
+  const dea: Nums = new Array(closes.length).fill(null);
+  const difVals: number[] = [];
+  const difIdx: number[] = [];
+  for (let i = 0; i < dif.length; i++) {
+    if (dif[i] != null) {
+      difVals.push(dif[i] as number);
+      difIdx.push(i);
+    }
+  }
+  const deaVals = ema(difVals, signal);
+  for (let j = 0; j < difIdx.length; j++) {
+    if (deaVals[j] != null) dea[difIdx[j]] = deaVals[j];
+  }
+  const hist: Nums = closes.map((_, i) =>
+    dif[i] != null && dea[i] != null ? ((dif[i] as number) - (dea[i] as number)) * 2 : null,
+  );
+  return { dif, dea, hist };
+}
+
+/** RSI（Wilder 平滑，国内软件常用 SMA(X,N,1) 等价 Wilder） */
+export function rsi(closes: number[], period = 14): Nums {
+  const out: Nums = new Array(closes.length).fill(null);
+  if (closes.length <= period) return out;
+  let avgGain = 0;
+  let avgLoss = 0;
+  // 首段：前 period 个变动的简单均值
+  for (let i = 1; i <= period; i++) {
+    const ch = closes[i] - closes[i - 1];
+    if (ch > 0) avgGain += ch;
+    else avgLoss -= ch;
+  }
+  avgGain /= period;
+  avgLoss /= period;
+  out[period] = avgLoss === 0 ? 100 : 100 - 100 / (1 + avgGain / avgLoss);
+  // Wilder 平滑
+  for (let i = period + 1; i < closes.length; i++) {
+    const ch = closes[i] - closes[i - 1];
+    const gain = ch > 0 ? ch : 0;
+    const loss = ch < 0 ? -ch : 0;
+    avgGain = (avgGain * (period - 1) + gain) / period;
+    avgLoss = (avgLoss * (period - 1) + loss) / period;
+    out[i] = avgLoss === 0 ? 100 : 100 - 100 / (1 + avgGain / avgLoss);
+  }
+  return out;
+}
+
+/** KDJ(9,3,3) */
+export function kdj(
+  bars: KBar[],
+  n = 9,
+  m1 = 3,
+  m2 = 3,
+): { k: Nums; d: Nums; j: Nums } {
+  const len = bars.length;
+  const k: Nums = new Array(len).fill(null);
+  const d: Nums = new Array(len).fill(null);
+  const j: Nums = new Array(len).fill(null);
+  let prevK = 50;
+  let prevD = 50;
+  for (let i = 0; i < len; i++) {
+    const from = Math.max(0, i - n + 1);
+    let hh = -Infinity;
+    let ll = Infinity;
+    for (let x = from; x <= i; x++) {
+      hh = Math.max(hh, bars[x].high);
+      ll = Math.min(ll, bars[x].low);
+    }
+    const rsv = hh === ll ? 50 : ((bars[i].close - ll) / (hh - ll)) * 100;
+    const kv = (2 * prevK + rsv) / m1; // 国内口径 K = 2/3 前值 + 1/3 RSV
+    const dv = (2 * prevD + kv) / m2;
+    prevK = kv;
+    prevD = dv;
+    k[i] = kv;
+    d[i] = dv;
+    j[i] = 3 * kv - 2 * dv;
+  }
+  return { k, d, j };
+}