feat(tls-fingerprint): 新增 TLS 指纹 Profile 数据库管理及代码质量优化

新增功能：
- 新增 TLS 指纹 Profile CRUD 管理（Ent schema + 迁移 + Admin API + 前端管理界面）
- 支持账号绑定数据库中的自定义 TLS Profile，或随机选择（profile_id=-1）
- HTTPUpstream.DoWithTLS 接口从 bool 改为 *tlsfingerprint.Profile，支持按账号指定 Profile
- AccountUsageService 注入 TLSFingerprintProfileService，统一 usage 场景与网关的 Profile 解析逻辑

代码优化：
- 删除已被 TLSFingerprintProfileService 完全取代的 registry.go 死代码（418 行）
- 提取 3 个 dialer 的重复 TLS 握手逻辑为 performTLSHandshake() 共用函数
- 修复 GetTLSFingerprintProfileID 缺少 json.Number 处理的 bug
- gateway_service.Forward 中 ResolveTLSProfile 从重试循环内重复调用改为预解析局部变量
- 删除冗余的 buildClientHelloSpec() 单行 wrapper 和 int64(e.ID) 无效转换
- tls_fingerprint_profile_cache.go 日志从 log.Printf 改为 slog 结构化日志
- dialer_capture_test.go 添加 //go:build integration 标签，防止 CI 失败
- 去重 TestProfileExpectation 类型至共享 test_types_test.go
- 修复 9 个测试文件缺少 tlsfingerprint import 的编译错误
- 修复 error_policy_integration_test.go 中 handleError 回调签名被错误替换的问题

backend/ent/migrate/schema.go

@@ -673,6 +673,30 @@ var (
 		Columns:    SettingsColumns,
 		PrimaryKey: []*schema.Column{SettingsColumns[0]},
 	}
+	// TLSFingerprintProfilesColumns holds the columns for the "tls_fingerprint_profiles" table.
+	TLSFingerprintProfilesColumns = []*schema.Column{
+		{Name: "id", Type: field.TypeInt64, Increment: true},
+		{Name: "created_at", Type: field.TypeTime, SchemaType: map[string]string{"postgres": "timestamptz"}},
+		{Name: "updated_at", Type: field.TypeTime, SchemaType: map[string]string{"postgres": "timestamptz"}},
+		{Name: "name", Type: field.TypeString, Unique: true, Size: 100},
+		{Name: "description", Type: field.TypeString, Nullable: true, Size: 2147483647},
+		{Name: "enable_grease", Type: field.TypeBool, Default: false},
+		{Name: "cipher_suites", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "curves", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "point_formats", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "signature_algorithms", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "alpn_protocols", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "supported_versions", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "key_share_groups", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "psk_modes", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+		{Name: "extensions", Type: field.TypeJSON, Nullable: true, SchemaType: map[string]string{"postgres": "jsonb"}},
+	}
+	// TLSFingerprintProfilesTable holds the schema information for the "tls_fingerprint_profiles" table.
+	TLSFingerprintProfilesTable = &schema.Table{
+		Name:       "tls_fingerprint_profiles",
+		Columns:    TLSFingerprintProfilesColumns,
+		PrimaryKey: []*schema.Column{TLSFingerprintProfilesColumns[0]},
+	}
 	// UsageCleanupTasksColumns holds the columns for the "usage_cleanup_tasks" table.
 	UsageCleanupTasksColumns = []*schema.Column{
 		{Name: "id", Type: field.TypeInt64, Increment: true},
@@ -1111,6 +1135,7 @@ var (
 		RedeemCodesTable,
 		SecuritySecretsTable,
 		SettingsTable,
+		TLSFingerprintProfilesTable,
 		UsageCleanupTasksTable,
 		UsageLogsTable,
 		UsersTable,
@@ -1175,6 +1200,9 @@ func init() {
 	SettingsTable.Annotation = &entsql.Annotation{
 		Table: "settings",
 	}
+	TLSFingerprintProfilesTable.Annotation = &entsql.Annotation{
+		Table: "tls_fingerprint_profiles",
+	}
 	UsageCleanupTasksTable.Annotation = &entsql.Annotation{
 		Table: "usage_cleanup_tasks",
 	}