feat: 소프트 딜리트 기능 전면 구현 완료

## 주요 변경사항
- Company, Equipment, License, Warehouse Location 모든 화면에 소프트 딜리트 구현
- 관리자 권한으로 삭제된 데이터 조회 가능 (includeInactive 파라미터)
- 데이터 무결성 보장을 위한 논리 삭제 시스템 완성

## 기능 개선
- 각 리스트 컨트롤러에 toggleIncludeInactive() 메서드 추가
- UI에 "비활성 포함" 체크박스 추가 (관리자 전용)
- API 데이터소스에 includeInactive 파라미터 지원

## 문서 정리
- 불필요한 문서 파일 제거 및 재구성
- CLAUDE.md 프로젝트 상태 업데이트 (진행률 80%)
- 테스트 결과 문서화 (test20250812v01.md)

## UI 컴포넌트
- Equipment 화면 위젯 모듈화 (custom_dropdown_field, equipment_basic_info_section)
- 폼 유효성 검증 강화

🤖 Generated with [Claude Code](https://claude.ai/code)

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

lib/screens/equipment/widgets/custom_dropdown_field.dart

@@ -0,0 +1,178 @@
+import 'package:flutter/material.dart';
+
+/// 드롭다운 기능이 있는 재사용 가능한 TextFormField 위젯
+class CustomDropdownField extends StatefulWidget {
+  final String label;
+  final String hint;
+  final bool required;
+  final TextEditingController controller;
+  final FocusNode focusNode;
+  final List<String> items;
+  final Function(String) onChanged;
+  final Function(String)? onFieldSubmitted;
+  final String? Function(String)? getAutocompleteSuggestion;
+  final VoidCallback onDropdownPressed;
+  final LayerLink layerLink;
+  final GlobalKey fieldKey;
+
+  const CustomDropdownField({
+    Key? key,
+    required this.label,
+    required this.hint,
+    required this.required,
+    required this.controller,
+    required this.focusNode,
+    required this.items,
+    required this.onChanged,
+    this.onFieldSubmitted,
+    this.getAutocompleteSuggestion,
+    required this.onDropdownPressed,
+    required this.layerLink,
+    required this.fieldKey,
+  }) : super(key: key);
+
+  @override
+  State<CustomDropdownField> createState() => _CustomDropdownFieldState();
+}
+
+class _CustomDropdownFieldState extends State<CustomDropdownField> {
+  bool _isProgrammaticChange = false;
+  OverlayEntry? _overlayEntry;
+
+  @override
+  void dispose() {
+    _removeDropdown();
+    super.dispose();
+  }
+
+  void _showDropdown() {
+    _removeDropdown();
+    
+    final RenderBox renderBox = widget.fieldKey.currentContext!.findRenderObject() as RenderBox;
+    final size = renderBox.size;
+    
+    _overlayEntry = OverlayEntry(
+      builder: (context) => Positioned(
+        width: size.width,
+        child: CompositedTransformFollower(
+          link: widget.layerLink,
+          showWhenUnlinked: false,
+          offset: const Offset(0, 45),
+          child: Material(
+            elevation: 4,
+            borderRadius: BorderRadius.circular(4),
+            child: Container(
+              decoration: BoxDecoration(
+                color: Colors.white,
+                border: Border.all(color: Colors.grey.shade300),
+                borderRadius: BorderRadius.circular(4),
+                boxShadow: [
+                  BoxShadow(
+                    color: Colors.grey.withValues(alpha: 0.3),
+                    spreadRadius: 1,
+                    blurRadius: 3,
+                    offset: const Offset(0, 1),
+                  ),
+                ],
+              ),
+              constraints: const BoxConstraints(maxHeight: 200),
+              child: SingleChildScrollView(
+                child: Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: widget.items.map((item) {
+                    return GestureDetector(
+                      behavior: HitTestBehavior.opaque,
+                      onTap: () {
+                        setState(() {
+                          _isProgrammaticChange = true;
+                          widget.controller.text = item;
+                        });
+                        widget.onChanged(item);
+                        WidgetsBinding.instance.addPostFrameCallback((_) {
+                          _isProgrammaticChange = false;
+                        });
+                        _removeDropdown();
+                      },
+                      child: Container(
+                        padding: const EdgeInsets.symmetric(
+                          horizontal: 16,
+                          vertical: 12,
+                        ),
+                        width: double.infinity,
+                        child: Text(item),
+                      ),
+                    );
+                  }).toList(),
+                ),
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+    
+    Overlay.of(context).insert(_overlayEntry!);
+  }
+
+  void _removeDropdown() {
+    if (_overlayEntry != null) {
+      _overlayEntry!.remove();
+      _overlayEntry = null;
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        CompositedTransformTarget(
+          link: widget.layerLink,
+          child: TextFormField(
+            key: widget.fieldKey,
+            controller: widget.controller,
+            focusNode: widget.focusNode,
+            decoration: InputDecoration(
+              labelText: widget.label,
+              hintText: widget.hint,
+              suffixIcon: IconButton(
+                icon: const Icon(Icons.arrow_drop_down),
+                onPressed: () {
+                  widget.onDropdownPressed();
+                  _showDropdown();
+                },
+              ),
+            ),
+            onChanged: (value) {
+              if (!_isProgrammaticChange) {
+                widget.onChanged(value);
+              }
+            },
+            onFieldSubmitted: widget.onFieldSubmitted,
+          ),
+        ),
+        // 자동완성 후보 표시
+        if (widget.getAutocompleteSuggestion != null)
+          Builder(
+            builder: (context) {
+              final suggestion = widget.getAutocompleteSuggestion!(widget.controller.text);
+              if (suggestion != null && suggestion.length > widget.controller.text.length) {
+                return Padding(
+                  padding: const EdgeInsets.only(left: 12, top: 2),
+                  child: Text(
+                    suggestion,
+                    style: const TextStyle(
+                      color: Color(0xFF1976D2),
+                      fontWeight: FontWeight.bold,
+                      fontSize: 13,
+                    ),
+                  ),
+                );
+              }
+              return const SizedBox.shrink();
+            },
+          ),
+      ],
+    );
+  }
+}