feat: 添加 E-Parti 启动画面及情绪颜色引导功能

主要变更：
1. 新增 ep_splash.png 作为应用启动时的展示图像。
2. 更新 Info.plist 中的应用名称和相关描述，替换为 "E-Parti"。
3. 引入 EPSignatureColorGuideView 和 EPEmotionColorStorage，支持用户选择和保存专属情绪颜色。
4. 在 AppDelegate 中集成情绪颜色引导逻辑，确保用户首次登录时能够选择专属颜色。

此更新旨在提升用户体验，增强应用的品牌识别度，并提供个性化的情绪表达功能。

YuMi/E-P/NewMoments/Controllers/EPMomentPublishViewController.m

@@ -47,6 +47,19 @@ NSString *const EPMomentPublishSuccessNotification = @"EPMomentPublishSuccessNot
     [super viewDidLoad];
     self.view.backgroundColor = [UIColor colorWithRed:0x0C/255.0 green:0x05/255.0 blue:0x27/255.0 alpha:1.0];
     [self setupUI];
+    
+    // 自动加载用户专属颜色
+    [self loadUserSignatureColor];
+}
+
+/// 加载用户专属颜色作为默认选中
+- (void)loadUserSignatureColor {
+    NSString *signatureColor = [EPEmotionColorStorage userSignatureColor];
+    if (signatureColor) {
+        self.selectedEmotionColor = signatureColor;
+        [self updateEmotionButtonAppearance];
+        NSLog(@"[Publish] 自动选中专属颜色: %@", signatureColor);
+    }
 }
 
 - (void)setupUI {
@@ -131,6 +144,10 @@ NSString *const EPMomentPublishSuccessNotification = @"EPMomentPublishSuccessNot
 
 - (void)onEmotionButtonTapped {
     EPEmotionColorPicker *picker = [[EPEmotionColorPicker alloc] init];
+    
+    // 预选中当前颜色（如果有）
+    picker.preselectedColor = self.selectedEmotionColor;
+    
     __weak typeof(self) weakSelf = self;
     picker.onColorSelected = ^(NSString *hexColor) {
         __strong typeof(weakSelf) self = weakSelf;
@@ -316,7 +333,15 @@ NSString *const EPMomentPublishSuccessNotification = @"EPMomentPublishSuccessNot
 
 - (UIView *)navView { if (!_navView) { _navView = [UIView new]; _navView.backgroundColor = [UIColor clearColor]; } return _navView; }
 - (UIButton *)backButton { if (!_backButton) { _backButton = [UIButton buttonWithType:UIButtonTypeCustom]; [_backButton setImage:[UIImage imageNamed:@"common_nav_back"] forState:UIControlStateNormal]; [_backButton addTarget:self action:@selector(onBack) forControlEvents:UIControlEventTouchUpInside]; } return _backButton; }
-- (UILabel *)titleLabel { if (!_titleLabel) { _titleLabel = [UILabel new]; _titleLabel.text = @"图文发布"; _titleLabel.textColor = [DJDKMIMOMColor mainTextColor]; _titleLabel.font = [UIFont systemFontOfSize:17]; } return _titleLabel; }
+- (UILabel *)titleLabel { 
+    if (!_titleLabel) { 
+        _titleLabel = [UILabel new]; 
+        _titleLabel.text = @"图文发布"; 
+        _titleLabel.textColor = [UIColor whiteColor]; // 白色适配深色背景
+        _titleLabel.font = [UIFont systemFontOfSize:17]; 
+    } 
+    return _titleLabel; 
+}
 - (UIButton *)publishButton { 
     if (!_publishButton) { 
         _publishButton = [UIButton buttonWithType:UIButtonTypeCustom]; 
@@ -338,18 +363,39 @@ NSString *const EPMomentPublishSuccessNotification = @"EPMomentPublishSuccessNot
     return _publishButton; 
 }
 - (UIView *)contentView { if (!_contentView) { _contentView = [UIView new]; _contentView.backgroundColor = [UIColor clearColor]; } return _contentView; }
-- (SZTextView *)textView { if (!_textView) { _textView = [SZTextView new]; _textView.placeholder = @"Enter Content"; _textView.textColor = [DJDKMIMOMColor mainTextColor]; _textView.placeholderTextColor = [DJDKMIMOMColor secondTextColor]; _textView.font = [UIFont systemFontOfSize:15]; _textView.delegate = self; } return _textView; }
-- (UILabel *)limitLabel { if (!_limitLabel) { _limitLabel = [UILabel new]; _limitLabel.text = @"0/500"; _limitLabel.textColor = [DJDKMIMOMColor mainTextColor]; _limitLabel.font = [UIFont systemFontOfSize:12]; } return _limitLabel; }
+- (SZTextView *)textView { 
+    if (!_textView) { 
+        _textView = [SZTextView new]; 
+        _textView.placeholder = @"Enter Content"; 
+        _textView.textColor = [UIColor whiteColor]; // 白色文本适配深色背景
+        _textView.placeholderTextColor = [[UIColor whiteColor] colorWithAlphaComponent:0.4]; // 半透明白色占位符
+        _textView.backgroundColor = [[UIColor whiteColor] colorWithAlphaComponent:0.08]; // 轻微背景色
+        _textView.layer.cornerRadius = 12;
+        _textView.layer.masksToBounds = YES;
+        _textView.font = [UIFont systemFontOfSize:15]; 
+        _textView.delegate = self; 
+    } 
+    return _textView; 
+}
+- (UILabel *)limitLabel { 
+    if (!_limitLabel) { 
+        _limitLabel = [UILabel new]; 
+        _limitLabel.text = @"0/500"; 
+        _limitLabel.textColor = [[UIColor whiteColor] colorWithAlphaComponent:0.6]; // 浅色适配深色背景
+        _limitLabel.font = [UIFont systemFontOfSize:12]; 
+    } 
+    return _limitLabel; 
+}
 - (UIView *)lineView { if (!_lineView) { _lineView = [UIView new]; _lineView.backgroundColor = [DJDKMIMOMColor dividerColor]; } return _lineView; }
 - (UIButton *)emotionButton { 
     if (!_emotionButton) { 
         _emotionButton = [UIButton buttonWithType:UIButtonTypeCustom]; 
         [_emotionButton setTitle:@"🎨  Add Emotion" forState:UIControlStateNormal]; 
-        [_emotionButton setTitleColor:[DJDKMIMOMColor mainTextColor] forState:UIControlStateNormal]; 
+        [_emotionButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal]; // 白色文本
         _emotionButton.titleLabel.font = [UIFont systemFontOfSize:15];
         _emotionButton.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
         _emotionButton.contentEdgeInsets = UIEdgeInsetsMake(0, 15, 0, 0);
-        _emotionButton.backgroundColor = [[UIColor whiteColor] colorWithAlphaComponent:0.06];
+        _emotionButton.backgroundColor = [[UIColor whiteColor] colorWithAlphaComponent:0.08]; // 稍微提亮背景
         _emotionButton.layer.cornerRadius = 8;
         _emotionButton.layer.masksToBounds = YES;
         [_emotionButton addTarget:self action:@selector(onEmotionButtonTapped) forControlEvents:UIControlEventTouchUpInside];