refactor: 전체 프론트엔드 하드코딩 색상 → CSS 변수 일괄 치환

447+ 파일, 4500+ 줄 변경:
- gray-* → border/bg-muted/text-foreground/text-muted-foreground
- blue-* → primary/ring
- red-* → destructive
- green-* → emerald (일관성)
- indigo-* → primary
- yellow/orange → amber (통일)
- dark mode 변형도 시맨틱 토큰으로 변환

Made-with: Cursor

frontend/components/dataflow/external-call/FieldMappingEditor.tsx

@@ -188,9 +188,9 @@ export const FieldMappingEditor: React.FC<FieldMappingEditorProps> = ({
                   <Label className="text-xs">{direction === "inbound" ? "외부 필드" : "내부 필드"}</Label>
                   <div className="mt-1 flex items-center gap-1">
                     {direction === "inbound" ? (
-                      <Globe className="h-3 w-3 text-blue-500" />
+                      <Globe className="h-3 w-3 text-primary" />
                     ) : (
-                      <Database className="h-3 w-3 text-green-500" />
+                      <Database className="h-3 w-3 text-emerald-500" />
                     )}
                     <Input
                       value={mapping.sourceField}
@@ -212,9 +212,9 @@ export const FieldMappingEditor: React.FC<FieldMappingEditorProps> = ({
                   <Label className="text-xs">{direction === "inbound" ? "내부 필드" : "외부 필드"}</Label>
                   <div className="mt-1 flex items-center gap-1">
                     {direction === "inbound" ? (
-                      <Database className="h-3 w-3 text-green-500" />
+                      <Database className="h-3 w-3 text-emerald-500" />
                     ) : (
-                      <Globe className="h-3 w-3 text-blue-500" />
+                      <Globe className="h-3 w-3 text-primary" />
                     )}
                     {direction === "inbound" && currentTable ? (
                       <Select