fix: align business reports and record task migration progress

pkg/task/output.go

@@ -0,0 +1,63 @@
+package task
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"sync"
+	"unicode/utf8"
+)
+
+type outputKey struct{}
+
+// Output collects bounded execution details without changing the method contract.
+// A timed-out method may still write, so snapshots and writes must be synchronized.
+type Output struct {
+	mu        sync.Mutex
+	text      string
+	truncated bool
+}
+
+func WithOutput(ctx context.Context) (context.Context, *Output) {
+	output := &Output{}
+	return context.WithValue(ctx, outputKey{}, output), output
+}
+
+// Logf records operational counts and progress. Do not include credentials or
+// whole request/response bodies. Outside a task execution it is a no-op.
+func Logf(ctx context.Context, format string, args ...any) {
+	if ctx == nil {
+		return
+	}
+	output, _ := ctx.Value(outputKey{}).(*Output)
+	if output == nil {
+		return
+	}
+	line := fmt.Sprintf(format, args...)
+	output.mu.Lock()
+	defer output.mu.Unlock()
+	const limit = 3000 // Reserve space for the executor's final status.
+	if output.truncated {
+		return
+	}
+	remaining := limit - len(output.text)
+	if len(line)+1 > remaining {
+		cut := max(0, remaining-1)
+		for cut > 0 && !utf8.RuneStart(line[cut]) {
+			cut--
+		}
+		line = line[:cut]
+		output.truncated = true
+	}
+	output.text += line + "\n"
+}
+
+func (output *Output) String() string {
+	output.mu.Lock()
+	defer output.mu.Unlock()
+	text := strings.TrimSpace(output.text)
+	if output.truncated {
+		text += "\n...(过程详情已截断)"
+	}
+	return text
+}