Refactor entire codebase and rewrite documentation

Sources/DataLiteCore/Protocols/ConnectionTraceDelegate.swift

@@ -0,0 +1,22 @@
+import Foundation
+
+/// A delegate that receives SQL statement trace callbacks.
+///
+/// Conforming types can inspect SQL before and after parameter expansion for logging, diagnostics,
+/// or profiling. Register a trace delegate with ``ConnectionProtocol/add(trace:)``.
+///
+/// - Important: Callbacks execute synchronously on SQLite’s internal thread. Keep implementations
+///   lightweight to avoid slowing down query execution.
+public protocol ConnectionTraceDelegate: AnyObject {
+    /// Represents traced SQL text before and after parameter substitution.
+    typealias Trace = (unexpandedSQL: String, expandedSQL: String)
+    
+    /// Called before a SQL statement is executed.
+    ///
+    /// Use to trace or log executed statements for debugging or profiling.
+    ///
+    /// - Parameters:
+    ///   - connection: The active database connection.
+    ///   - sql: A tuple with the original and expanded SQL text.
+    func connection(_ connection: ConnectionProtocol, trace sql: Trace)
+}