feat: 模块化命令框架 + runbook 严格断言与查询结果回传

- core/module: 命令模板、门控（feature flag/confirm/dry-run）、ecode 错误标签、ResultFormatter
- runbook executor: http.get/http.post/assert.json(expect_success 严格断言)、目标主机管理、任务落库、最终 stdout 直接回传
- cf 模块: /cf dns list 支持域名自动解析 zone_id；dns list/zones/workers list 格式化回传；API success:false 判真失败
- 全部 CF/CPA runbook 接入严格断言，杜绝假阳性 success
- 新增 cpa/cfdav/mail/sub 模块与 runbooks；QQ 订阅到期提醒调度
- Web 后台: 模块设置(CF/CPA/cfdav/AI)、OPS 任务、渠道管理、审计页

internal/module/mail/commands.go

@@ -0,0 +1,25 @@
+package mail
+
+import (
+	"fmt"
+
+	coremodule "ops-assistant/internal/core/module"
+)
+
+func commandSpecs() []coremodule.CommandSpec {
+	return []coremodule.CommandSpec{
+		{
+			Prefixes: []string{"/mail status"},
+			Template: coremodule.CommandTemplate{
+				RunbookName: "mail_status",
+				Gate: coremodule.Gate{
+					NeedFlag:    "enable_module_mail",
+					AllowDryRun: true,
+				},
+				DryRunMsg:  "🧪 dry-run: 将执行 /mail status（未实际执行）",
+				SuccessMsg: func(jobID uint) string { return fmt.Sprintf("✅ /mail status 已执行，job=%d", jobID) },
+			},
+			ErrPrefix: "/mail status 执行失败: ",
+		},
+	}
+}

internal/module/mail/module.go

@@ -0,0 +1,40 @@
+package mail
+
+import (
+	"strings"
+
+	"ops-assistant/internal/core/command"
+	"ops-assistant/internal/core/ecode"
+	coremodule "ops-assistant/internal/core/module"
+	"ops-assistant/internal/core/runbook"
+	"gorm.io/gorm"
+)
+
+type Module struct {
+	db     *gorm.DB
+	exec   *runbook.Executor
+	runner *coremodule.Runner
+}
+
+func New(db *gorm.DB, exec *runbook.Executor) *Module {
+	return &Module{db: db, exec: exec, runner: coremodule.NewRunner(db, exec)}
+}
+
+func (m *Module) Handle(userID int64, cmd *command.ParsedCommand) (string, error) {
+	text := strings.TrimSpace(cmd.Raw)
+	if text == "/mail" || strings.HasPrefix(text, "/mail help") {
+		return "Mail 模块\n- /mail status [--dry-run]", nil
+	}
+	specs := commandSpecs()
+	if sp, ok := coremodule.MatchCommand(text, specs); ok {
+		jobID, out, err := coremodule.ExecTemplate(m.runner, userID, cmd.Raw, sp.Template)
+		if err != nil {
+			return ecode.Tag(ecode.ErrStepFailed, coremodule.FormatExecError(sp, err)), nil
+		}
+		if out == "dry-run" {
+			return ecode.Tag("OK", coremodule.FormatDryRunMessage(sp.Template)), nil
+		}
+		return ecode.Tag("OK", coremodule.FormatSuccessMessage(sp.Template, jobID)), nil
+	}
+	return ecode.Tag(ecode.ErrStepFailed, "Mail 模块已接入，当前支持：/mail status, /mail help"), nil
+}