feat(backend): unified response helpers, refresh token, security hardening

- new resp package (OK/Page/Fail/BadRequest/.../InternalErr): unified error
  envelope {detail, code?}, sanitized 500s (full error logged server-side,
  generic message to client - stops DB error leakage), pagination envelope
  {items,total,page,page_size}; migrate 200+ inline c.JSON error sites
- refresh token: 7d rotation tokens (SHA-256 hashed at rest), public
  POST /auth/refresh with single-use rotation, POST /auth/logout revokes
  all user refresh tokens (endpoint previously missing - frontend 404)
- security: gh-ost command line password masked in task status payload;
  Instance.MarshalJSON guarantees encrypted passwords never leave the API
  (removes reliance on per-handler manual masking); production (DEBUG=false)
  with default JWT secret now auto-generates and persists a random secret
- safe.Go recover wrapper for background goroutines (instance probe,
  gh-ost async)
- delete dead service layer (zero callers)
- fix pre-existing go vet unkeyed bson.E literals

backend/internal/ghost/ghost.go

@@ -5,31 +5,34 @@ import (
 	"context"
 	"fmt"
 	"os/exec"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
+
+	"sql-platform/internal/safe"
 )
 
 // GhOstTask defines a gh-ost execution task
 type GhOstTask struct {
-	Host           string `json:"host"`
-	Port           int    `json:"port,omitempty"`
-	User           string `json:"user"`
-	Password       string `json:"password"`
-	Database       string `json:"database"`
-	Table          string `json:"table"`
-	Alter          string `json:"alter"`              // e.g. "ADD COLUMN status INT NOT NULL DEFAULT 0"
-	ChunkSize      int    `json:"chunk_size,omitempty"`
-	MaxLoad        string `json:"max_load,omitempty"`
-	CriticalLoad   string `json:"critical_load,omitempty"`
-	MaxLagMillis   int    `json:"max_lag_millis,omitempty"`
-	AllowOnMaster  bool   `json:"allow_on_master"`
-	DryRun         bool   `json:"dry_run"`
-	Execute        bool   `json:"execute"`
-	ExactRowCount  bool   `json:"exact_row_count"`
-	PostponeCutOver bool  `json:"postpone_cut_over"`
-	AliyunRDS      bool   `json:"aliyun_rds,omitempty"`  // --aliyun-rds
-	AWSAurora      bool   `json:"aws_aurora,omitempty"`  // --aws
+	Host            string `json:"host"`
+	Port            int    `json:"port,omitempty"`
+	User            string `json:"user"`
+	Password        string `json:"password"`
+	Database        string `json:"database"`
+	Table           string `json:"table"`
+	Alter           string `json:"alter"` // e.g. "ADD COLUMN status INT NOT NULL DEFAULT 0"
+	ChunkSize       int    `json:"chunk_size,omitempty"`
+	MaxLoad         string `json:"max_load,omitempty"`
+	CriticalLoad    string `json:"critical_load,omitempty"`
+	MaxLagMillis    int    `json:"max_lag_millis,omitempty"`
+	AllowOnMaster   bool   `json:"allow_on_master"`
+	DryRun          bool   `json:"dry_run"`
+	Execute         bool   `json:"execute"`
+	ExactRowCount   bool   `json:"exact_row_count"`
+	PostponeCutOver bool   `json:"postpone_cut_over"`
+	AliyunRDS       bool   `json:"aliyun_rds,omitempty"` // --aliyun-rds
+	AWSAurora       bool   `json:"aws_aurora,omitempty"` // --aws
 }
 
 // GhOstResult holds the execution result
@@ -121,7 +124,7 @@ func RunGhOst(ctx context.Context, task GhOstTask, ghOstPath string) (*GhOstResu
 	err := cmd.Run()
 
 	result := &GhOstResult{
-		Command:  "gh-ost " + strings.Join(args, " "),
+		Command:  "gh-ost " + maskSecrets(strings.Join(args, " ")),
 		Duration: time.Since(start).String(),
 		Output:   stdout.String(),
 	}
@@ -145,7 +148,7 @@ func RunGhOstAsync(task GhOstTask, ghOstPath string, cb ProgressCallback) string
 	Manager.tasks[taskID] = &GhOstResult{TaskID: taskID}
 	Manager.mu.Unlock()
 
-	go func() {
+	run := func() {
 		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Hour)
 		defer cancel()
 
@@ -165,7 +168,7 @@ func RunGhOstAsync(task GhOstTask, ghOstPath string, cb ProgressCallback) string
 
 		result := &GhOstResult{
 			TaskID:   taskID,
-			Command:  "gh-ost " + strings.Join(args, " "),
+			Command:  "gh-ost " + maskSecrets(strings.Join(args, " ")),
 			Duration: time.Since(start).String(),
 			Output:   stdout.String(),
 			Success:  err == nil,
@@ -183,11 +186,17 @@ func RunGhOstAsync(task GhOstTask, ghOstPath string, cb ProgressCallback) string
 		if cb != nil {
 			cb(taskID, result.Output)
 		}
-	}()
+	}
+	safe.Go("ghost:"+taskID, run)
 
 	return taskID
 }
 
+// maskSecrets 将命令行中的密码参数值替换为 ******，防止经任务状态接口回传前端
+func maskSecrets(cmdline string) string {
+	return regexp.MustCompile(`(--password=)([^ ]+)`).ReplaceAllString(cmdline, `$1******`)
+}
+
 // GetTaskStatus returns the status of an async task
 func (m *TaskManager) GetTaskStatus(taskID string) (string, *GhOstResult) {
 	m.mu.RLock()