chore: 初始提交 Fonu 1.0.2

- 公网反代：Nginx 状态卡片（版本 / 运行状态 / 配置校验 / 端口监听）
- 部署设置第一、二梯队（HTTPS 开关、安全头、限流、连接数、仅中国大陆 IP）
- 隧道检测兼容 frps v0.68 / v0.71（V2 与旧版端点）
- 恢复被清空的 internal/frp/store.go、internal/api/ddns_handler.go、web/src/views/DdnsView.vue

internal/db/db.go

@@ -0,0 +1,113 @@
+package db
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	_ "modernc.org/sqlite"
+)
+
+func Open(path string) (*sql.DB, error) {
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return nil, err
+	}
+
+	dsn := fmt.Sprintf("file:%s?_pragma=foreign_keys(1)&_pragma=busy_timeout(5000)", path)
+	conn, err := sql.Open("sqlite", dsn)
+	if err != nil {
+		return nil, err
+	}
+	conn.SetMaxOpenConns(1)
+	return conn, nil
+}
+
+func Migrate(ctx context.Context, conn *sql.DB, migrationsDir string) error {
+	if err := ensureMigrationsTable(ctx, conn); err != nil {
+		return err
+	}
+
+	entries, err := os.ReadDir(migrationsDir)
+	if err != nil {
+		return err
+	}
+
+	var files []string
+	for _, e := range entries {
+		if e.IsDir() || !strings.HasSuffix(e.Name(), ".sql") {
+			continue
+		}
+		files = append(files, e.Name())
+	}
+	sort.Strings(files)
+
+	for _, name := range files {
+		version, err := parseVersion(name)
+		if err != nil {
+			return err
+		}
+		applied, err := isApplied(ctx, conn, version)
+		if err != nil {
+			return err
+		}
+		if applied {
+			continue
+		}
+
+		content, err := os.ReadFile(filepath.Join(migrationsDir, name))
+		if err != nil {
+			return err
+		}
+
+		tx, err := conn.BeginTx(ctx, nil)
+		if err != nil {
+			return err
+		}
+
+		if _, err := tx.ExecContext(ctx, string(content)); err != nil {
+			_ = tx.Rollback()
+			return fmt.Errorf("migration %s failed: %w", name, err)
+		}
+		if _, err := tx.ExecContext(ctx, `INSERT INTO schema_migrations(version) VALUES (?)`, version); err != nil {
+			_ = tx.Rollback()
+			return fmt.Errorf("record migration %s failed: %w", name, err)
+		}
+		if err := tx.Commit(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func ensureMigrationsTable(ctx context.Context, conn *sql.DB) error {
+	_, err := conn.ExecContext(ctx, `
+		CREATE TABLE IF NOT EXISTS schema_migrations (
+			version INTEGER PRIMARY KEY,
+			applied_at TEXT NOT NULL DEFAULT (datetime('now'))
+		)
+	`)
+	return err
+}
+
+func parseVersion(name string) (int, error) {
+	parts := strings.SplitN(name, "_", 2)
+	if len(parts) == 0 {
+		return 0, fmt.Errorf("invalid migration filename: %s", name)
+	}
+	var version int
+	if _, err := fmt.Sscanf(parts[0], "%d", &version); err != nil {
+		return 0, fmt.Errorf("invalid migration version in %s: %w", name, err)
+	}
+	return version, nil
+}
+
+func isApplied(ctx context.Context, conn *sql.DB, version int) (bool, error) {
+	var count int
+	err := conn.QueryRowContext(ctx, `SELECT COUNT(1) FROM schema_migrations WHERE version = ?`, version).Scan(&count)
+	return count > 0, err
+}

internal/db/db_test.go

@@ -0,0 +1,24 @@
+package db
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+)
+
+func TestMigrate(t *testing.T) {
+	dir := t.TempDir()
+	conn, err := Open(filepath.Join(dir, "fonu.db"))
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	defer conn.Close()
+
+	migrationsDir := filepath.Join("..", "..", "migrations")
+	if err := Migrate(context.Background(), conn, migrationsDir); err != nil {
+		t.Fatalf("migrate failed: %v", err)
+	}
+	if err := Migrate(context.Background(), conn, migrationsDir); err != nil {
+		t.Fatalf("second migrate failed: %v", err)
+	}
+}