chore: 恢复旧布局基线（迁移改动丢失后重建，apps/packages 布局暂存）

server/internal/db/sqlite.go

@@ -0,0 +1,97 @@
+package db
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"os"
+	"strings"
+
+	_ "modernc.org/sqlite"
+)
+
+// openSQLite 打开 SQLite 库文件;文件不存在时报错而非静默建空库。
+// DSN 追加 busy_timeout / foreign_keys pragma。
+func openSQLite(c ConnReq) (*sql.DB, error) {
+	path := c.Database
+	if path == "" {
+		path = c.Host
+	}
+	if path == "" {
+		return nil, fmt.Errorf("SQLite 需要 database 填文件路径")
+	}
+	dsn := path
+	switch {
+	case path == ":memory:":
+		// 统一走 file: URI 以便携带 _pragma 参数
+		dsn = "file::memory:"
+	case strings.HasPrefix(path, "file:"):
+		// 调用方自带 URI 参数,不再做存在性检查
+	default:
+		if _, err := os.Stat(path); err != nil {
+			return nil, fmt.Errorf("SQLite 文件不存在: %s", path)
+		}
+		dsn = "file:" + path
+	}
+	sep := "?"
+	if strings.Contains(dsn, "?") {
+		sep = "&"
+	}
+	dsn += sep + "_pragma=busy_timeout(5000)&_pragma=foreign_keys(1)"
+	return sql.Open("sqlite", dsn)
+}
+
+func quoteSQLiteIdent(s string) string {
+	return `"` + strings.ReplaceAll(s, `"`, `""`) + `"`
+}
+
+func listDatabasesSQLite(_ *sql.DB) ([]string, error) {
+	return []string{"main"}, nil
+}
+
+func listTablesSQLite(ctx context.Context, db *sql.DB, _ string) ([]string, error) {
+	rows, err := db.QueryContext(ctx, `SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%' ORDER BY 1`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	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 listColumnsSQLite(ctx context.Context, dbh *sql.DB, _, table string) ([]ColumnInfo, error) {
+	rows, err := dbh.QueryContext(ctx, `PRAGMA table_info(`+quoteSQLiteIdent(table)+`)`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []ColumnInfo
+	for rows.Next() {
+		var cid int
+		var name, typ string
+		var notnull, pk int
+		var def sql.NullString
+		if err := rows.Scan(&cid, &name, &typ, &notnull, &def, &pk); err != nil {
+			return nil, err
+		}
+		col := ColumnInfo{Name: name, Type: typ, Nullable: notnull == 0}
+		if pk > 0 {
+			col.Key = "PRI"
+		}
+		if def.Valid {
+			col.Default = def.String
+		}
+		out = append(out, col)
+	}
+	if out == nil {
+		out = []ColumnInfo{}
+	}
+	return out, rows.Err()
+}