桌面 GUI 外链修复 + 主题顺序调整（含结构扁平化进行中的工作区基线）

- 集成 tauri-plugin-opener：Cargo/lib.rs/capabilities/npm 四处接线，新增 src/openExternal.ts（桌面走 opener，浏览器回退 window.open，相对路径绝对化）
- 关于页 4 个链接、活动栏官网菜单、代理错误横幅 2 处健康检查链接全部改走 openExternal，桌面端可正常跳转
- 设置→外观 主题顺序调整为 深色/浅色/跟随系统
- release 二进制重编并验证（浏览器实测关于页链接可开文档页）
- 附带工作区中未提交的扁平化重构现状（另一会话进行中）
- homepage 落地页与文档终检通过（8787 / 与 /docs 双 200）

server/internal/proxy/stream.go

@@ -0,0 +1,145 @@
+package proxy
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ProxyHTTPStream 以 NDJSON 流式转发响应（SSE / chunked / 大响应体）。
+// 事件序列：meta → chunk* → end | error
+type streamEvent struct {
+	Type    string            `json:"type"`
+	Status  int               `json:"status,omitempty"`
+	Headers map[string]string `json:"headers,omitempty"`
+	Data    string            `json:"data,omitempty"`
+	Message string            `json:"message,omitempty"`
+	TimeMS  int64             `json:"timeMs,omitempty"`
+	Size    int               `json:"size,omitempty"`
+}
+
+func (h *Handler) ProxyHTTPStream(c *gin.Context) {
+	var spec HttpSpec
+	if err := c.ShouldBindJSON(&spec); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid HttpSpec", "detail": err.Error()})
+		return
+	}
+
+	method := normalizeMethod(spec.Method)
+	u, err := ValidateURL(spec.URL)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	query := u.Query()
+	for key, value := range spec.Query {
+		query.Set(key, value)
+	}
+	u.RawQuery = query.Encode()
+
+	var body io.Reader
+	if spec.Body != nil && spec.Body.Mode != "none" && method != http.MethodGet && method != http.MethodHead {
+		body = bytes.NewBufferString(spec.Body.Raw)
+	}
+
+	req, err := http.NewRequestWithContext(c.Request.Context(), method, u.String(), body)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "cannot create request", "detail": err.Error()})
+		return
+	}
+	for key, value := range spec.Headers {
+		if !isHopByHop(key) {
+			req.Header.Set(key, value)
+		}
+	}
+	if spec.Body != nil && spec.Body.Mode == "json" && req.Header.Get("Content-Type") == "" {
+		req.Header.Set("Content-Type", "application/json")
+	}
+
+	client := h.BaseClient
+	if spec.TimeoutMS > 0 {
+		client = &http.Client{Timeout: time.Duration(spec.TimeoutMS) * time.Millisecond}
+	} else {
+		// 流式场景默认不设整体超时（SSE 长连接），交给客户端断开
+		client = &http.Client{}
+	}
+
+	started := time.Now()
+	res, err := client.Do(req)
+	if err != nil {
+		c.JSON(http.StatusBadGateway, gin.H{"error": "upstream request failed", "detail": err.Error()})
+		return
+	}
+	defer res.Body.Close()
+
+	headers := make(map[string]string, len(res.Header))
+	for key, values := range res.Header {
+		headers[key] = joinNonEmpty(values)
+	}
+
+	flusher, ok := c.Writer.(http.Flusher)
+	if !ok {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "streaming unsupported"})
+		return
+	}
+	c.Header("Content-Type", "application/x-ndjson")
+	c.Header("Cache-Control", "no-cache")
+	c.Header("X-Accel-Buffering", "no")
+	c.Status(http.StatusOK)
+
+	enc := json.NewEncoder(c.Writer)
+	writeEvent := func(ev streamEvent) bool {
+		if err := enc.Encode(ev); err != nil {
+			return false
+		}
+		flusher.Flush()
+		return true
+	}
+
+	headers["content-type"] = res.Header.Get("Content-Type")
+	if !writeEvent(streamEvent{Type: "meta", Status: res.StatusCode, Headers: headers}) {
+		return
+	}
+
+	reader := bufio.NewReaderSize(res.Body, 32*1024)
+	buf := make([]byte, 16*1024)
+	total := 0
+	for {
+		n, readErr := reader.Read(buf)
+		if n > 0 {
+			total += n
+			ok := writeEvent(streamEvent{
+				Type: "chunk",
+				Data: base64.StdEncoding.EncodeToString(buf[:n]),
+				Size: n,
+			})
+			if !ok {
+				return
+			}
+		}
+		if readErr != nil {
+			break
+		}
+		if c.Request.Context().Err() != nil {
+			return
+		}
+	}
+	writeEvent(streamEvent{Type: "end", TimeMS: time.Since(started).Milliseconds(), Size: total})
+}
+
+func joinNonEmpty(values []string) string {
+	out := ""
+	for i, v := range values {
+		if i > 0 {
+			out += ", "
+		}
+		out += v
+	}
+	return out
+}