Refactor entire codebase and rewrite documentation

Sources/DataLiteCore/Enums/SQLiteValue.swift

@@ -0,0 +1,65 @@
+import Foundation
+
+/// An enumeration that represents raw SQLite values.
+///
+/// `SQLiteValue` encapsulates all fundamental SQLite storage classes. It is used to
+/// store values retrieved from or written to a SQLite database, providing a type-safe
+/// Swift representation for each supported data type.
+///
+/// - SeeAlso: [Datatypes In SQLite](https://sqlite.org/datatype3.html)
+///
+/// ## Topics
+///
+/// ### Enumeration Cases
+///
+/// - ``int(_:)``
+/// - ``real(_:)``
+/// - ``text(_:)``
+/// - ``blob(_:)``
+/// - ``null``
+public enum SQLiteValue: Equatable, Hashable, Sendable {
+    /// A 64-bit integer value.
+    case int(Int64)
+    
+    /// A double-precision floating-point value.
+    case real(Double)
+    
+    /// A text string encoded in UTF-8.
+    case text(String)
+    
+    /// Binary data (BLOB).
+    case blob(Data)
+    
+    /// A `NULL` value.
+    case null
+}
+
+public extension SQLiteValue {
+    /// A SQL literal representation of the value.
+    ///
+    /// Converts the current value into a string suitable for embedding directly in an SQL
+    /// statement. Strings are quoted and escaped, binary data is encoded in hexadecimal form, and
+    /// `NULL` is represented by the literal `NULL`.
+    var sqliteLiteral: String {
+        switch self {
+        case .int(let int):     "\(int)"
+        case .real(let real):   "\(real)"
+        case .text(let text):   "'\(text.replacingOccurrences(of: "'", with: "''"))'"
+        case .blob(let data):   "X'\(data.hex)'"
+        case .null:             "NULL"
+        }
+    }
+}
+
+extension SQLiteValue: CustomStringConvertible {
+    /// A textual representation of the value, identical to `sqliteLiteral`.
+    public var description: String {
+        sqliteLiteral
+    }
+}
+
+private extension Data {
+    var hex: String {
+        map { String(format: "%02hhX", $0) }.joined()
+    }
+}