feat: OpsxDB 桌面数据库客户端首版入库

含工作台/连库多引擎字段与 SSH·SSL、结果编辑、Redis 键浏览、
Tauri 桌面与 docs/落地页；排除本地构建产物与 sidecar 二进制。

apps/server/internal/db/mssql.go

@@ -0,0 +1,139 @@
+package db
+
+import (
+	"database/sql"
+	"fmt"
+	"net/url"
+	"strings"
+
+	_ "github.com/microsoft/go-mssqldb"
+)
+
+func openMSSQL(c ConnReq) (*sql.DB, error) {
+	host := c.Host
+	if host == "" {
+		host = "127.0.0.1"
+	}
+	port := c.Port
+	if port == 0 {
+		port = 1433
+	}
+	user := c.User
+	if user == "" {
+		user = "sa"
+	}
+	dbName := c.Database
+	if dbName == "" {
+		dbName = "master"
+	}
+	mode := EffectiveSSLMode(c)
+	q := url.Values{}
+	q.Set("database", dbName)
+	q.Set("connection timeout", "5")
+	switch mode {
+	case "disable":
+		q.Set("encrypt", "disable")
+	case "skip-verify":
+		q.Set("encrypt", "true")
+		q.Set("TrustServerCertificate", "true")
+		if ca := strings.TrimSpace(c.SSLCA); ca != "" {
+			q.Set("certificate", ca)
+		}
+	case "require", "verify-ca":
+		q.Set("encrypt", "true")
+		q.Set("TrustServerCertificate", "false")
+		ca := strings.TrimSpace(c.SSLCA)
+		if mode == "verify-ca" && ca == "" {
+			return nil, fmt.Errorf("verify-ca 模式需要填写 CA 证书路径")
+		}
+		if ca != "" {
+			// go-mssqldb msdsn certificate= builds RootCAs from PEM/DER
+			q.Set("certificate", ca)
+		}
+		if host != "" {
+			q.Set("hostnameincertificate", host)
+		}
+	default:
+		return nil, fmt.Errorf("未知 SSL 模式: %s", mode)
+	}
+	dsn := fmt.Sprintf("sqlserver://%s:%s@%s:%d?%s",
+		url.QueryEscape(user), url.QueryEscape(c.Password), host, port, q.Encode())
+	return sql.Open("sqlserver", dsn)
+}
+
+func listDatabasesMSSQL(db *sql.DB) ([]string, error) {
+	rows, err := db.Query(`SELECT name FROM sys.databases WHERE name NOT IN ('master','tempdb','model','msdb') ORDER BY name`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []string
+	for rows.Next() {
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			return nil, err
+		}
+		out = append(out, name)
+	}
+	return out, rows.Err()
+}
+
+func listTablesMSSQL(db *sql.DB, database string) ([]string, error) {
+	_ = database
+	rows, err := db.Query(`
+		SELECT TABLE_SCHEMA + '.' + TABLE_NAME
+		FROM INFORMATION_SCHEMA.TABLES
+		WHERE TABLE_TYPE = 'BASE TABLE'
+		ORDER BY 1`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []string
+	for rows.Next() {
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			return nil, err
+		}
+		out = append(out, name)
+	}
+	return out, rows.Err()
+}
+
+func listColumnsMSSQL(dbh *sql.DB, _, table string) ([]ColumnInfo, error) {
+	schema, t := splitSchemaTable(table)
+	if schema == "" {
+		schema = "dbo"
+	}
+	rows, err := dbh.Query(`
+		SELECT COLUMN_NAME, DATA_TYPE,
+			ISNULL(CAST(CHARACTER_MAXIMUM_LENGTH AS varchar), ''),
+			IS_NULLABLE, COLUMN_DEFAULT
+		FROM INFORMATION_SCHEMA.COLUMNS
+		WHERE TABLE_SCHEMA = @p1 AND TABLE_NAME = @p2
+		ORDER BY ORDINAL_POSITION`, schema, t)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []ColumnInfo
+	for rows.Next() {
+		var name, typ, extra, nullable string
+		var def sql.NullString
+		if err := rows.Scan(&name, &typ, &extra, &nullable, &def); err != nil {
+			return nil, err
+		}
+		if extra != "" && extra != "-1" {
+			typ = typ + "(" + extra + ")"
+		}
+		col := ColumnInfo{Name: name, Type: typ, Nullable: nullable == "YES"}
+		if def.Valid {
+			col.Default = def.String
+		}
+		out = append(out, col)
+	}
+	if out == nil {
+		out = []ColumnInfo{}
+	}
+	return out, rows.Err()
+}