feat: add BELO peak hour analysis chart

- New backend endpoint GET /quotes/:type/peak-hours
- Groups daily price data by hour to find peak frequency
- Bar chart showing how often each hour is the daily peak
- Only displayed for BELO currency in analysis page

apps/backend/src/modules/quotes/handlers/getPeakHours.ts

@@ -0,0 +1,95 @@
+import type { Context } from "hono";
+import type { QuoteType } from "../../../generated/prisma/client";
+import { cache } from "../../../lib/cache";
+import { prisma } from "../../../lib/prisma";
+import { parseLocalDate, startOfNextLocalDay } from "../../../lib/utils";
+
+const VALID_TYPES = ["BLUE", "BNA", "BELO"] as const;
+
+export async function getPeakHours(c: Context) {
+  const rawType = c.req.param("type")?.toUpperCase();
+
+  if (!VALID_TYPES.includes(rawType as (typeof VALID_TYPES)[number])) {
+    return c.json(
+      {
+        error: `Invalid quote type. Must be one of: ${VALID_TYPES.join(", ")}`,
+      },
+      400,
+    );
+  }
+
+  const type = rawType as QuoteType;
+  const startDateParam = c.req.query("startDate");
+  const endDateParam = c.req.query("endDate");
+
+  const now = new Date();
+  const startDate = startDateParam
+    ? parseLocalDate(startDateParam)
+    : new Date(now.getFullYear(), now.getMonth(), 1);
+  const endDate = endDateParam ? startOfNextLocalDay(endDateParam) : now;
+
+  if (Number.isNaN(startDate.getTime()) || Number.isNaN(endDate.getTime())) {
+    return c.json({ error: "Invalid date format. Use ISO 8601." }, 400);
+  }
+
+  const cacheKey = `quotes:peak-hours:${type}:${startDate.toISOString()}:${endDate.toISOString()}`;
+  const cached = cache.get(cacheKey);
+  if (cached) return c.json(cached);
+
+  const result = await prisma.$queryRaw<
+    Array<{
+      hour: number;
+      frequency: number;
+      avg_peak_buy: number;
+      min_peak_buy: number;
+      max_peak_buy: number;
+    }>
+  >`
+    WITH daily_peaks AS (
+      SELECT
+        DATE("timeStamp") AS day,
+        EXTRACT(HOUR FROM "timeStamp")::int AS peak_hour,
+        buy::numeric AS peak_buy,
+        ROW_NUMBER() OVER (
+          PARTITION BY DATE("timeStamp")
+          ORDER BY buy::numeric DESC
+        ) AS rn
+      FROM "quotes_history"
+      WHERE "type" = ${rawType}::"QuoteType"
+        AND "timeStamp" >= ${startDate}::timestamptz
+        AND "timeStamp" < ${endDate}::timestamptz
+    )
+    SELECT
+      peak_hour AS hour,
+      COUNT(*)::int AS frequency,
+      AVG(peak_buy)::float8 AS avg_peak_buy,
+      MIN(peak_buy)::float8 AS min_peak_buy,
+      MAX(peak_buy)::float8 AS max_peak_buy
+    FROM daily_peaks
+    WHERE rn = 1
+    GROUP BY peak_hour
+    ORDER BY peak_hour ASC
+  `;
+
+  const totalDays = await prisma.$queryRaw<Array<{ count: number }>>`
+    SELECT COUNT(DISTINCT DATE("timeStamp"))::int AS count
+    FROM "quotes_history"
+    WHERE "type" = ${rawType}::"QuoteType"
+      AND "timeStamp" >= ${startDate}::timestamptz
+      AND "timeStamp" < ${endDate}::timestamptz
+  `;
+
+  const response = {
+    totalDays: totalDays[0]?.count ?? 0,
+    peaks: result.map((r) => ({
+      hour: r.hour,
+      frequency: r.frequency,
+      avgPeakBuy: r.avg_peak_buy,
+      minPeakBuy: r.min_peak_buy,
+      maxPeakBuy: r.max_peak_buy,
+    })),
+  };
+
+  cache.set(cacheKey, response);
+  return c.json(response);
+}

apps/backend/src/modules/quotes/quotes.routes.ts

@@ -5,6 +5,7 @@ import { getDailyMinMax } from "./handlers/getDailyMinMax";
 import { getDailyQuotes } from "./handlers/getDailyQuotes";
 import { getHistoricalMinMax } from "./handlers/getHistoricalMinMax";
 import { getMonthlyLast } from "./handlers/getMonthlyLast";
+import { getPeakHours } from "./handlers/getPeakHours";
 import { getQuoteHistory } from "./handlers/getQuoteHistory";
 import { quoteEvents } from "./handlers/quoteEvents";
 
@@ -15,6 +16,7 @@ app.get("/monthly-last", getMonthlyLast);
 app.get("/:type/history", getQuoteHistory);
 app.get("/:type/daily", getDailyQuotes);
 app.get("/:type/min-max", getDailyMinMax);
+app.get("/:type/peak-hours", getPeakHours);
 app.get("/:type/historical/min-max", getHistoricalMinMax);
 app.get("/fetch", fetchQuotes);
 app.get("/events", quoteEvents);