fix: 后台思考身份混淆 + 静默模式视觉理解 + QQ卡片解析 + 仪表盘状态修复

- 后台思考对话历史增加标签说明，严格区分群聊中不同发送者
- 静默观察模式传入图片URL并预处理，供后台思考参考
- 视觉+OCR双模型结果合并格式优化，避免LLM误认为多张图片
- QQ卡片消息(CQ:json)正确解析标题/类型，不再丢失为[JSON]
- 进程管理器stop()在进程为null时重置pid/startTime，消除矛盾状态

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/platform-bridge/internal/adapter/qq/adapter.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"net/url"
 	"regexp"
 	"strings"
 	"sync"
@@ -506,6 +507,55 @@ func (a *Adapter) ReadMessages(ctx context.Context, msgCh chan<- *OBv11Message)
 	}
 }
 
+// parseJSONCardTitle extracts a human-readable title from a QQ JSON card.
+// The data is the raw JSON string from the "data" field of a json-type message segment.
+func parseJSONCardTitle(data string) string {
+	var card struct {
+		App    string `json:"app"`
+		Prompt string `json:"prompt"`
+		Title  string `json:"title"`
+		Desc   string `json:"desc"`
+		Meta   struct {
+			Detail1 struct {
+				Title string `json:"title"`
+				Desc  string `json:"desc"`
+			} `json:"detail_1"`
+			News struct {
+				Title string `json:"title"`
+				Desc  string `json:"desc"`
+			} `json:"news"`
+			Music struct {
+				Title string `json:"title"`
+				Desc  string `json:"desc"`
+			} `json:"music"`
+		} `json:"meta"`
+	}
+	if err := json.Unmarshal([]byte(data), &card); err != nil {
+		return "[卡片消息]"
+	}
+
+	// Prefer prompt (e.g. "[分享]标题"), then meta titles, then top-level title.
+	if card.Prompt != "" {
+		return "[卡片] " + card.Prompt
+	}
+	if card.Meta.Detail1.Title != "" {
+		return "[卡片] " + card.Meta.Detail1.Title
+	}
+	if card.Meta.News.Title != "" {
+		return "[卡片] " + card.Meta.News.Title
+	}
+	if card.Meta.Music.Title != "" {
+		return "[卡片] " + card.Meta.Music.Title
+	}
+	if card.Title != "" {
+		return "[卡片] " + card.Title
+	}
+	if card.Desc != "" {
+		return "[卡片] " + card.Desc
+	}
+	return "[卡片消息]"
+}
+
 // cqSimplifyMap maps CQ code types to simplified Chinese labels.
 var cqSimplifyMap = map[string]string{
 	"image":  "[图片]",
@@ -528,6 +578,15 @@ func simplifyCQCodes(s string) string {
 				break
 			}
 		}
+		if typ == "json" {
+			// Parse data= field from [CQ:json,data=URL_ENCODED_JSON]
+			if dataVal := extractCQParam(match, "data"); dataVal != "" {
+				if decoded, err := url.QueryUnescape(dataVal); err == nil {
+					return parseJSONCardTitle(decoded)
+				}
+			}
+			return "[卡片消息]"
+		}
 		if label, ok := cqSimplifyMap[typ]; ok {
 			return label
 		}
@@ -535,6 +594,24 @@ func simplifyCQCodes(s string) string {
 	})
 }
 
+// extractCQParam extracts a named parameter value from a CQ code string.
+// e.g. extractCQParam("[CQ:json,data=hello%20world]", "data") → "hello%20world"
+func extractCQParam(cqCode, paramName string) string {
+	prefix := paramName + "="
+	idx := strings.Index(cqCode, prefix)
+	if idx < 0 {
+		return ""
+	}
+	val := cqCode[idx+len(prefix):]
+	// Value ends at "," or "]"
+	for i, c := range val {
+		if c == ',' || c == ']' {
+			return val[:i]
+		}
+	}
+	return val
+}
+
 // extractText retrieves plain text from an OBv11 message.
 // CQ codes are converted to human-readable form where applicable (e.g. [CQ:at,qq=xxx] → @xxx).
 func extractText(msg *OBv11Message) string {
@@ -576,6 +653,16 @@ func extractText(msg *OBv11Message) string {
 				case "reply":
 					// Reply is handled separately in ToUnified with reply text.
 					text += "[回复]"
+				case "json":
+					if data, ok := s["data"].(map[string]interface{}); ok {
+						if inner, ok := data["data"].(string); ok && inner != "" {
+							text += parseJSONCardTitle(inner)
+						} else {
+							text += "[卡片消息]"
+						}
+					} else {
+						text += "[卡片消息]"
+					}
 				}
 			}
 		}