feat: 深色模式圆形揭示动画 + B 站私信规则

主题切换:
- 抽出 useTheme 全局单例，主题在挂载前初始化，登录页不再闪白底
- 用 View Transitions API 以点击点为圆心做圆形揭示；不支持的浏览器
  加 .no-vt 类退化为整页淡变，两者互斥避免揭示区露出过渡中的颜色
- 尊重 prefers-reduced-motion；过渡被浏览器跳过时静默降级为直接切换
- 主题按钮图标旋转切换

新规则:
- bilibili-private-message：向指定 UID 发送 B 站私信，
  发送者 UID 自动从账号 Cookie 读取

视觉打磨:
- 统计数字改为缓出计数动画，等宽数字避免跳动时抖动
- 补 :focus-visible 焦点环

说明：当前 SDK 未提供视频投稿接口，无法支持定时投稿视频，
详见 docs/bilibili-config.md。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

drivers/bilibili/model.go

@@ -5,6 +5,8 @@ const (
 	AccountType = "bilibili"
 	// RuleTypeDynamic 发送 B 站动态的规则类型标识
 	RuleTypeDynamic = "bilibili-dynamic"
+	// RuleTypePrivateMessage 发送 B 站私信的规则类型标识
+	RuleTypePrivateMessage = "bilibili-private-message"
 )
 
 type BiliAccount struct {
@@ -14,3 +16,10 @@ type BiliAccount struct {
 type BiliDynamicConfig struct {
 	Msg string `json:"msg"`
 }
+
+// BiliPrivateMessageConfig 私信规则配置
+type BiliPrivateMessageConfig struct {
+	// 接收者的 UID 列表
+	ReceiverUids []int64 `json:"receiver_uids"`
+	Msg          string  `json:"msg"`
+}

drivers/bilibili/privateMessage.go

@@ -0,0 +1,80 @@
+package bilibili
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/CuteReimu/bilibili/v2"
+	"github.com/ssdomei232/goodBaby/internal/retry"
+	"github.com/ssdomei232/goodBaby/model"
+)
+
+// 私信消息类型：1 为文字
+const privateMsgTypeText = 1
+
+// SendBiliPrivateMessage 向配置中的每个 UID 发送一条 B 站私信
+func SendBiliPrivateMessage(ctx context.Context, rule *model.Rule) error {
+	client, err := getBiliClient(rule)
+	if err != nil {
+		return fmt.Errorf("获取B站客户端失败: %w", err)
+	}
+
+	config, err := getPrivateMessageConfig(rule)
+	if err != nil {
+		return err
+	}
+
+	// 发私信需要带上自己的 UID，从账号信息里取
+	account, err := client.GetAccountInformation()
+	if err != nil {
+		return fmt.Errorf("获取B站账号信息失败(cookie 可能已失效): %w", err)
+	}
+	if account == nil || account.Mid == 0 {
+		return fmt.Errorf("B站 cookie 无效或已过期")
+	}
+
+	var fails []string
+	for _, uid := range config.ReceiverUids {
+		err := retry.Do(ctx, func() error {
+			_, err := client.SendPrivateMessage(bilibili.SendPrivateMessageParam{
+				SenderUid:    account.Mid,
+				ReceiverId:   int(uid),
+				ReceiverType: 1,
+				MsgType:      privateMsgTypeText,
+				Timestamp:    int(time.Now().Unix()),
+				Content:      buildTextContent(config.Msg),
+			})
+			return err
+		})
+		if err != nil {
+			fails = append(fails, fmt.Sprintf("UID %d: %v", uid, err))
+		}
+	}
+
+	if len(fails) > 0 {
+		return fmt.Errorf("%d/%d 条私信发送失败: %s",
+			len(fails), len(config.ReceiverUids), strings.Join(fails, "; "))
+	}
+	return nil
+}
+
+// buildTextContent 文字私信的 content 是一个 JSON 字符串 {"content":"..."}
+func buildTextContent(msg string) string {
+	payload, err := json.Marshal(map[string]string{"content": msg})
+	if err != nil {
+		// msg 是普通字符串，序列化不会失败；兜底也返回合法 JSON
+		return `{"content":""}`
+	}
+	return string(payload)
+}
+
+func getPrivateMessageConfig(rule *model.Rule) (*BiliPrivateMessageConfig, error) {
+	var config BiliPrivateMessageConfig
+	if err := json.Unmarshal([]byte(rule.ConfigJson), &config); err != nil {
+		return nil, fmt.Errorf("解析B站私信规则配置失败: %w", err)
+	}
+	return &config, nil
+}

drivers/bilibili/ruleConfigChecker.go

@@ -31,6 +31,57 @@ func (v *BilibiliDynamicRuleValidator) Validate(configJSON string) error {
 	return nil
 }
 
+// BilibiliPrivateMessageRuleValidator B站私信规则验证器
+type BilibiliPrivateMessageRuleValidator struct{}
+
+func (v *BilibiliPrivateMessageRuleValidator) GetType() string {
+	return RuleTypePrivateMessage
+}
+
+func (v *BilibiliPrivateMessageRuleValidator) Validate(configJSON string) error {
+	var config BiliPrivateMessageConfig
+	if err := json.Unmarshal([]byte(configJSON), &config); err != nil {
+		return fmt.Errorf("解析B站私信规则配置失败: %v", err)
+	}
+
+	if config.Msg == "" {
+		return fmt.Errorf("B站私信规则配置中 msg 不能为空")
+	}
+
+	if len(config.ReceiverUids) == 0 {
+		return fmt.Errorf("B站私信规则配置中 receiver_uids 不能为空")
+	}
+
+	for _, uid := range config.ReceiverUids {
+		if uid <= 0 {
+			return fmt.Errorf("B站私信规则配置中存在非法的 UID: %d", uid)
+		}
+	}
+
+	return nil
+}
+
+func (v *BilibiliPrivateMessageRuleValidator) Meta() meta.RuleMeta {
+	return meta.RuleMeta{
+		Type:        RuleTypePrivateMessage,
+		Label:       "发送 B 站私信",
+		Description: "触发时以关联的 B 站账号向指定用户发送私信。对方需要能接收你的私信。",
+		Docs:        "docs/bilibili-config.md",
+		AccountType: AccountType,
+		Fields: []meta.Field{
+			{
+				Key:         "receiver_uids",
+				Label:       "接收者 UID",
+				Type:        meta.FieldNumberList,
+				Required:    true,
+				Placeholder: "2",
+				Help:        "对方空间地址 space.bilibili.com/ 后面的那串数字",
+			},
+			{Key: "msg", Label: "私信内容", Type: meta.FieldTextarea, Required: true},
+		},
+	}
+}
+
 func (v *BilibiliDynamicRuleValidator) Meta() meta.RuleMeta {
 	return meta.RuleMeta{
 		Type:        RuleTypeDynamic,

drivers/bilibili/runner.go

@@ -19,3 +19,16 @@ func (e *BilibiliDynamicExecutor) Execute(ctx context.Context, rule *model.Rule)
 
 	return SendBiliDynamicMsg(ctx, rule)
 }
+
+// BilibiliPrivateMessageExecutor B站私信执行器
+type BilibiliPrivateMessageExecutor struct{}
+
+func (e *BilibiliPrivateMessageExecutor) GetType() string {
+	return RuleTypePrivateMessage
+}
+
+func (e *BilibiliPrivateMessageExecutor) Execute(ctx context.Context, rule *model.Rule) error {
+	log.Printf("执行B站私信规则: %s (ID: %d)", rule.Name, rule.ID)
+
+	return SendBiliPrivateMessage(ctx, rule)
+}