feat(RepeaterTable): 컬럼 너비 자동 맞춤 기능 추가

- 균등 분배 / 자동 맞춤 토글 방식으로 변경
- measureTextWidth(): 한글/영문/숫자별 픽셀 계산
- applyAutoFitWidths(): 글자 너비 기준 컬럼 조정
- 계산 규칙 결과 필드를 드롭다운으로 변경

frontend/lib/registry/components/universal-form-modal/TableSectionRenderer.tsx

@@ -2,7 +2,7 @@
 
 import React, { useState, useEffect, useCallback, useMemo } from "react";
 import { Button } from "@/components/ui/button";
-import { Plus, Columns } from "lucide-react";
+import { Plus, Columns, AlignJustify } from "lucide-react";
 import { cn } from "@/lib/utils";
 import { apiClient } from "@/lib/api/client";
 
@@ -170,8 +170,8 @@ export function TableSectionRenderer({
   // 체크박스 선택 상태
   const [selectedRows, setSelectedRows] = useState<Set<number>>(new Set());
   
-  // 균등 분배 트리거
-  const [equalizeWidthsTrigger, setEqualizeWidthsTrigger] = useState(0);
+  // 너비 조정 트리거 (홀수: 자동맞춤, 짝수: 균등분배)
+  const [widthTrigger, setWidthTrigger] = useState(0);
   
   // 동적 데이터 소스 활성화 상태
   const [activeDataSources, setActiveDataSources] = useState<Record<string, string>>({});
@@ -438,12 +438,21 @@ export function TableSectionRenderer({
             <Button
               variant="outline"
               size="sm"
-              onClick={() => setEqualizeWidthsTrigger((prev) => prev + 1)}
+              onClick={() => setWidthTrigger((prev) => prev + 1)}
               className="h-7 text-xs px-2"
-              title="컬럼 너비 균등 분배"
+              title={widthTrigger % 2 === 0 ? "내용에 맞게 자동 조정" : "균등 분배"}
             >
-              <Columns className="h-3.5 w-3.5 mr-1" />
-              균등 분배
+              {widthTrigger % 2 === 0 ? (
+                <>
+                  <AlignJustify className="h-3.5 w-3.5 mr-1" />
+                  자동 맞춤
+                </>
+              ) : (
+                <>
+                  <Columns className="h-3.5 w-3.5 mr-1" />
+                  균등 분배
+                </>
+              )}
             </Button>
           )}
         </div>
@@ -478,7 +487,7 @@ export function TableSectionRenderer({
         onDataSourceChange={handleDataSourceChange}
         selectedRows={selectedRows}
         onSelectionChange={setSelectedRows}
-        equalizeWidthsTrigger={equalizeWidthsTrigger}
+        equalizeWidthsTrigger={widthTrigger}
       />
 
       {/* 항목 선택 모달 */}

frontend/lib/registry/components/universal-form-modal/modals/TableSectionSettingsModal.tsx

@@ -1232,12 +1232,27 @@ export function TableSectionSettingsModal({
 
                     {(tableConfig.calculations || []).map((calc, index) => (
                       <div key={index} className="flex items-center gap-2 border rounded-lg p-2 bg-muted/30">
-                        <Input
-                          value={calc.resultField}
-                          onChange={(e) => updateCalculation(index, { resultField: e.target.value })}
-                          placeholder="결과 필드"
-                          className="h-8 text-xs w-[150px]"
-                        />
+                        <Select
+                          value={calc.resultField || ""}
+                          onValueChange={(value) => updateCalculation(index, { resultField: value })}
+                        >
+                          <SelectTrigger className="h-8 text-xs w-[150px]">
+                            <SelectValue placeholder="결과 필드 선택" />
+                          </SelectTrigger>
+                          <SelectContent>
+                            {(tableConfig.columns || []).length === 0 ? (
+                              <SelectItem value="__no_columns__" disabled>
+                                컬럼 설정에서 먼저 컬럼을 추가하세요
+                              </SelectItem>
+                            ) : (
+                              (tableConfig.columns || []).map((col) => (
+                                <SelectItem key={col.field} value={col.field}>
+                                  {col.label || col.field}
+                                </SelectItem>
+                              ))
+                            )}
+                          </SelectContent>
+                        </Select>
                         <span className="text-xs text-muted-foreground">=</span>
                         <Input
                           value={calc.formula}