长任务 Agent Harness：上下文交接与断点续跑

{
  "schemaVersion": 1,
  "taskId": "order-app-42",
  "revision": 7,
  "contractHash": "sha256:...",
  "artifactHash": "sha256:...",
  "checks": [
    {"id": "login-browser", "status": "passed", "evidenceId": "ev-91"}
  ],
  "effects": [
    {"operationId": "seed-order-8", "status": "unknown"}
  ],
  "nextAction": "reconcile seed-order-8 before retry"
}

package main

import (
	"crypto/sha256"
	"encoding/hex"
	"fmt"
)

type Check struct {
	ID           string
	Passed       bool
	ArtifactHash string
}

type Handoff struct {
	SchemaVersion int
	TaskID        string
	Revision      int
	ArtifactHash  string
	Checks        []Check
	UnknownOps    []string
}

func digest(data []byte) string {
	sum := sha256.Sum256(data)
	return hex.EncodeToString(sum[:])
}

func resume(h Handoff, taskID string, artifact []byte, required []string) (string, error) {
	if h.SchemaVersion != 1 || h.TaskID != taskID || h.Revision < 1 {
		return "", fmt.Errorf("invalid handoff identity or version")
	}
	currentHash := digest(artifact)
	if currentHash != h.ArtifactHash {
		return "revalidate", nil
	}
	if len(h.UnknownOps) > 0 {
		return "reconcile:" + h.UnknownOps[0], nil
	}
	verified := make(map[string]bool)
	for _, check := range h.Checks {
		if check.Passed && check.ArtifactHash == currentHash {
			verified[check.ID] = true
		}
	}
	for _, id := range required {
		if !verified[id] {
			return "verify:" + id, nil
		}
	}
	return "completed", nil
}

func main() {
	artifact := []byte("order-app revision 7")
	hash := digest(artifact)
	h := Handoff{
		SchemaVersion: 1, TaskID: "order-app-42", Revision: 7,
		ArtifactHash: hash,
		Checks: []Check{{ID: "login", Passed: true, ArtifactHash: hash}},
		UnknownOps: []string{"seed-order-8"},
	}
	required := []string{"login", "orders"}
	for _, input := range [][]byte{[]byte("changed artifact"), artifact} {
		action, err := resume(h, "order-app-42", input, required)
		if err != nil {
			panic(err)
		}
		fmt.Println(action)
	}
	h.UnknownOps = nil
	action, err := resume(h, "order-app-42", artifact, required)
	if err != nil {
		panic(err)
	}
	fmt.Println(action)
}

revalidate
reconcile:seed-order-8
verify:orders