feat: 수주등록 모달 및 범용 컴포넌트 개발

- 범용 컴포넌트 3종 개발 및 레지스트리 등록:
  * AutocompleteSearchInput: 자동완성 검색 입력 컴포넌트
  * EntitySearchInput: 엔티티 검색 모달 컴포넌트
  * ModalRepeaterTable: 모달 기반 반복 테이블 컴포넌트

- 수주등록 전용 컴포넌트:
  * OrderCustomerSearch: 거래처 검색 (AutocompleteSearchInput 래퍼)
  * OrderItemRepeaterTable: 품목 관리 (ModalRepeaterTable 래퍼)
  * OrderRegistrationModal: 수주등록 메인 모달

- 백엔드 API:
  * Entity 검색 API (멀티테넌시 지원)
  * 수주 등록 API (자동 채번)

- 화면 편집기 통합:
  * 컴포넌트 레지스트리에 등록
  * ConfigPanel을 통한 설정 기능
  * 드래그앤드롭으로 배치 가능

- 개발 문서:
  * 수주등록_화면_개발_계획서.md (상세 설계 문서)

frontend/lib/registry/components/entity-search-input/EntitySearchInputComponent.tsx

@@ -0,0 +1,126 @@
+"use client";
+
+import React, { useState, useEffect } from "react";
+import { Input } from "@/components/ui/input";
+import { Button } from "@/components/ui/button";
+import { Search, X } from "lucide-react";
+import { EntitySearchModal } from "./EntitySearchModal";
+import { EntitySearchInputProps, EntitySearchResult } from "./types";
+import { cn } from "@/lib/utils";
+
+export function EntitySearchInputComponent({
+  tableName,
+  displayField,
+  valueField,
+  searchFields = [displayField],
+  mode = "combo",
+  placeholder = "검색...",
+  disabled = false,
+  filterCondition = {},
+  value,
+  onChange,
+  modalTitle = "검색",
+  modalColumns = [],
+  showAdditionalInfo = false,
+  additionalFields = [],
+  className,
+}: EntitySearchInputProps) {
+  const [modalOpen, setModalOpen] = useState(false);
+  const [displayValue, setDisplayValue] = useState("");
+  const [selectedData, setSelectedData] = useState<EntitySearchResult | null>(null);
+
+  // value가 변경되면 표시값 업데이트
+  useEffect(() => {
+    if (value && selectedData) {
+      setDisplayValue(selectedData[displayField] || "");
+    } else {
+      setDisplayValue("");
+      setSelectedData(null);
+    }
+  }, [value, displayField]);
+
+  const handleSelect = (newValue: any, fullData: EntitySearchResult) => {
+    setSelectedData(fullData);
+    setDisplayValue(fullData[displayField] || "");
+    onChange?.(newValue, fullData);
+  };
+
+  const handleClear = () => {
+    setDisplayValue("");
+    setSelectedData(null);
+    onChange?.(null, null);
+  };
+
+  const handleOpenModal = () => {
+    if (!disabled) {
+      setModalOpen(true);
+    }
+  };
+
+  return (
+    <div className={cn("space-y-2", className)}>
+      {/* 입력 필드 */}
+      <div className="flex gap-2">
+        <div className="relative flex-1">
+          <Input
+            value={displayValue}
+            onChange={(e) => setDisplayValue(e.target.value)}
+            placeholder={placeholder}
+            disabled={disabled}
+            readOnly={mode === "modal" || mode === "combo"}
+            className="h-8 text-xs sm:h-10 sm:text-sm pr-8"
+          />
+          {displayValue && !disabled && (
+            <Button
+              type="button"
+              variant="ghost"
+              size="sm"
+              onClick={handleClear}
+              className="absolute right-1 top-1/2 -translate-y-1/2 h-6 w-6 p-0"
+            >
+              <X className="h-3 w-3" />
+            </Button>
+          )}
+        </div>
+
+        {(mode === "modal" || mode === "combo") && (
+          <Button
+            type="button"
+            onClick={handleOpenModal}
+            disabled={disabled}
+            className="h-8 text-xs sm:h-10 sm:text-sm"
+          >
+            <Search className="h-4 w-4" />
+          </Button>
+        )}
+      </div>
+
+      {/* 추가 정보 표시 */}
+      {showAdditionalInfo && selectedData && additionalFields.length > 0 && (
+        <div className="text-xs text-muted-foreground space-y-1 px-2">
+          {additionalFields.map((field) => (
+            <div key={field} className="flex gap-2">
+              <span className="font-medium">{field}:</span>
+              <span>{selectedData[field] || "-"}</span>
+            </div>
+          ))}
+        </div>
+      )}
+
+      {/* 검색 모달 */}
+      <EntitySearchModal
+        open={modalOpen}
+        onOpenChange={setModalOpen}
+        tableName={tableName}
+        displayField={displayField}
+        valueField={valueField}
+        searchFields={searchFields}
+        filterCondition={filterCondition}
+        modalTitle={modalTitle}
+        modalColumns={modalColumns}
+        onSelect={handleSelect}
+      />
+    </div>
+  );
+}
+