feat: add token usage tracking and leaderboard

- Add token_usage table with composite unique index for claw_id + date
- Add API endpoints: POST /token, GET /token/leaderboard, GET /token/stats
- Add TokenLeaderboard component with daily/total period toggle
- Add CLI commands: `token` and `stats` for reporting and viewing usage
- Add Redis caching for leaderboard with 1-minute TTL
- Add shared utilities: authenticateRequest, getTodayDateString
- Use UPSERT pattern for atomic token updates
- Add i18n translations (en/zh) for new UI elements

app/api/v1/token/leaderboard/route.ts

@@ -0,0 +1,113 @@
+import { NextRequest, NextResponse } from "next/server";
+import { eq, desc, sql } from "drizzle-orm";
+import { db } from "@/lib/db";
+import { claws, tokenUsage } from "@/lib/db/schema";
+import {
+  getTokenLeaderboardCache,
+  setTokenLeaderboardCache,
+} from "@/lib/redis";
+import { getTodayDateString } from "@/lib/utils";
+
+interface LeaderboardEntry {
+  clawId: string;
+  clawName: string;
+  inputTokens: number;
+  outputTokens: number;
+  totalTokens: number;
+}
+
+export async function GET(req: NextRequest) {
+  try {
+    const { searchParams } = new URL(req.url);
+    const period = searchParams.get("period") || "daily";
+    const limit = Math.min(parseInt(searchParams.get("limit") || "100"), 100);
+
+    if (period !== "daily" && period !== "total") {
+      return NextResponse.json(
+        { error: "Invalid period. Must be 'daily' or 'total'" },
+        { status: 400 }
+      );
+    }
+
+    const today = getTodayDateString();
+
+    // Check cache
+    const cached = await getTokenLeaderboardCache(
+      period as "daily" | "total",
+      today
+    );
+    if (cached) {
+      return NextResponse.json(JSON.parse(cached));
+    }
+
+    let leaderboard: LeaderboardEntry[];
+
+    if (period === "daily") {
+      // Daily leaderboard - tokens for today only
+      const dailyData = await db
+        .select({
+          clawId: tokenUsage.clawId,
+          clawName: claws.name,
+          inputTokens: tokenUsage.inputTokens,
+          outputTokens: tokenUsage.outputTokens,
+          totalTokens: sql<number>`(${tokenUsage.inputTokens} + ${tokenUsage.outputTokens})`.as("totalTokens"),
+        })
+        .from(tokenUsage)
+        .innerJoin(claws, eq(tokenUsage.clawId, claws.id))
+        .where(eq(tokenUsage.date, today))
+        .orderBy(desc(sql`(${tokenUsage.inputTokens} + ${tokenUsage.outputTokens})`))
+        .limit(limit);
+
+      leaderboard = dailyData.map((d) => ({
+        clawId: d.clawId,
+        clawName: d.clawName,
+        inputTokens: d.inputTokens,
+        outputTokens: d.outputTokens,
+        totalTokens: d.inputTokens + d.outputTokens,
+      }));
+    } else {
+      // Total leaderboard - sum of all time
+      // Use a raw query for aggregation since Drizzle's groupBy is complex
+      const totalData = await db.execute(sql`
+        SELECT
+          t.claw_id AS clawId,
+          c.name AS clawName,
+          CAST(SUM(t.input_tokens) AS SIGNED) AS inputTokens,
+          CAST(SUM(t.output_tokens) AS SIGNED) AS outputTokens,
+          CAST(SUM(t.input_tokens + t.output_tokens) AS SIGNED) AS totalTokens
+        FROM token_usage t
+        JOIN claws c ON t.claw_id = c.id
+        GROUP BY t.claw_id, c.name
+        ORDER BY totalTokens DESC
+        LIMIT ${limit}
+      `);
+
+      leaderboard = totalData[0] as unknown as LeaderboardEntry[];
+    }
+
+    // Add rank
+    const responseData = {
+      period,
+      date: today,
+      leaderboard: leaderboard.map((item, index) => ({
+        rank: index + 1,
+        ...item,
+      })),
+    };
+
+    // Cache for 1 minute
+    await setTokenLeaderboardCache(
+      period as "daily" | "total",
+      today,
+      JSON.stringify(responseData)
+    );
+
+    return NextResponse.json(responseData);
+  } catch (error) {
+    console.error("Token leaderboard error:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}