`Ping()` does not validate connectivity for remote URLs

[ashmortar]

Ping() does not validate connectivity for remote URLs

When using remote database URLs (libsql://, https://, http://), the Ping() method always returns success, even when the host is unreachable. This makes it impossible to validate database connectivity during application startup or health checks.

Reproduction

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/tursodatabase/go-libsql"
)

func main() {
    // Non-existent host
    db, err := sql.Open("libsql", "libsql://unreachable-host.invalid?authToken=test")
    if err != nil {
        panic(err)
    }
    defer db.Close()
    
    // Should fail but returns nil
    err = db.Ping()
    fmt.Printf("Ping error: %v\n", err)  // Output: Ping error: <nil>
    
    // Actual failure only occurs when executing queries
    var result int
    err = db.QueryRow("SELECT 1").Scan(&result)
    fmt.Printf("Query error: %v\n", err)
    // Output: Query error: failed to execute query SELECT 1
    // error code = 1: Error executing statement: Hrana: `http error: `error trying to connect: dns error: failed to lookup address information: Name or service not known``
}

Expected Behavior

Ping() should attempt to establish a connection and return an error if the host is unreachable, following the standard database/sql driver behavior.

Current Behavior

The connection is only attempted when executing statements. Open(), Ping(), and even Conn() all succeed without validating connectivity.

Impact

Applications cannot:

• Validate database configuration at startup
• Implement proper health checks
• Fail fast on misconfigured connection strings

Suggested Fix

Implement the driver.Pinger interface to validate connectivity for remote URLs, or at minimum execute a simple query like SELECT 1 during Ping() to ensure the database is reachable.