feat: add filter options API endpoint

Add GET /api/warehouse/filters endpoint that returns distinct workshop
codes/names and handler names from both pressure gauge and thermometer
contract tables, filtering out noise values from the workshop column.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/api/warehouse/filters/route.ts

@@ -0,0 +1,71 @@
+import { NextResponse } from "next/server";
+import sql from "mssql";
+import { getPool } from "@/lib/db";
+import type { FilterOptions } from "@/types/warehouse";
+
+// Workshop code -> display name mapping
+const WORKSHOP_MAP: Record<string, string> = {
+  "1": "一车间",
+  "2": "二车间",
+  "3": "温度计车间",
+  "4": "四车间",
+  "5": "五车间",
+};
+
+export async function GET() {
+  try {
+    const pool = await getPool();
+
+    // Get distinct workshops from both contract tables
+    const workshopResult = await pool.request().query(`
+      SELECT DISTINCT 车间 AS code
+      FROM productionContractData.[26年压力表合同数据]
+      WHERE 车间 IS NOT NULL AND 车间 NOT IN (' ', '')
+        AND 车间 NOT LIKE '%取消%' AND 车间 NOT LIKE '%暂停%'
+        AND 车间 NOT LIKE '%变更%' AND 车间 NOT LIKE '%检%'
+        AND 车间 NOT LIKE '%重选%' AND 车间 NOT LIKE '%外购%'
+        AND 车间 NOT LIKE '%取%'
+      UNION
+      SELECT DISTINCT 车间 AS code
+      FROM productionContractData.[26年温度计合同数据]
+      WHERE 车间 IS NOT NULL AND 车间 NOT IN (' ', '')
+        AND 车间 NOT LIKE '%取消%' AND 车间 NOT LIKE '%暂停%'
+        AND 车间 NOT LIKE '%变更%' AND 车间 NOT LIKE '%检%'
+        AND 车间 NOT LIKE '%重选%' AND 车间 NOT LIKE '%外购%'
+        AND 车间 NOT LIKE '%取%'
+      ORDER BY code
+    `);
+
+    const workshops = workshopResult.recordset.map(
+      (r: { code: string }) => ({
+        code: r.code.trim(),
+        name: WORKSHOP_MAP[r.code.trim()] || r.code.trim(),
+      })
+    );
+
+    // Get distinct handlers
+    const handlerResult = await pool.request().query(`
+      SELECT DISTINCT 经办人 AS handler
+      FROM productionContractData.[26年压力表合同数据]
+      WHERE 经办人 IS NOT NULL AND 经办人 <> ''
+      UNION
+      SELECT DISTINCT 经办人 AS handler
+      FROM productionContractData.[26年温度计合同数据]
+      WHERE 经办人 IS NOT NULL AND 经办人 <> ''
+      ORDER BY handler
+    `);
+
+    const handlers = handlerResult.recordset.map(
+      (r: { handler: string }) => r.handler
+    );
+
+    const data: FilterOptions = { workshops, handlers };
+    return NextResponse.json(data);
+  } catch (error) {
+    console.error("Failed to fetch filter options:", error);
+    return NextResponse.json(
+      { error: "Failed to fetch filter options" },
+      { status: 500 }
+    );
+  }
+}