feat: add SQLite session store support

Add NewSQLiteSessionManager helper that creates an SCS session manager
backed by SQLite, allowing sessions to persist across server restarts.
The function handles table creation automatically.

session.go

@@ -2,11 +2,34 @@ package via
 
 import (
 	"context"
+	"database/sql"
 	"time"
 
+	"github.com/alexedwards/scs/sqlite3store"
 	"github.com/alexedwards/scs/v2"
 )
 
+// NewSQLiteSessionManager creates a session manager using SQLite for persistence.
+// Creates the sessions table if it doesn't exist.
+// The returned manager can be configured further (Lifetime, Cookie settings, etc.)
+// before passing to Options.SessionManager.
+func NewSQLiteSessionManager(db *sql.DB) (*scs.SessionManager, error) {
+	_, err := db.Exec(`
+		CREATE TABLE IF NOT EXISTS sessions (
+			token TEXT PRIMARY KEY,
+			data BLOB NOT NULL,
+			expiry REAL NOT NULL
+		);
+		CREATE INDEX IF NOT EXISTS sessions_expiry_idx ON sessions(expiry);
+	`)
+	if err != nil {
+		return nil, err
+	}
+	sm := scs.New()
+	sm.Store = sqlite3store.New(db)
+	return sm, nil
+}
+
 // Session provides access to the user's session data.
 // Session data persists across page views for the same browser.
 type Session struct {