refactor: Rename package from SwiftTUI to TUIKit

BREAKING CHANGE: Package name changed due to name collision with
existing rensbreur/SwiftTUI package.

Changes:
- Rename package from SwiftTUI to TUIKit in Package.swift
- Rename Sources/SwiftTUI to Sources/TUIKit
- Rename Sources/SwiftTUIExample to Sources/TUIKitExample
- Rename Tests/SwiftTUITests to Tests/TUIKitTests
- Rename SwiftTUI.swift to TUIKit.swift
- Update all imports: import SwiftTUI -> import TUIKit
- Update all code references: SwiftTUI.renderToBuffer -> TUIKit.renderToBuffer
- Update documentation comments
- Rename swiftTUIVersion to tuiKitVersion

All 181 tests passing.

Sources/TUIKit/Modifiers/KeyPressModifier.swift

@@ -0,0 +1,125 @@
+//
+//  KeyPressModifier.swift
+//  TUIKit
+//
+//  A modifier for handling keyboard events.
+//
+
+/// A modifier that adds a key press handler to a view.
+///
+/// The handler returns a Bool indicating whether the event was consumed.
+/// If false is returned, the event continues to propagate to other handlers.
+public struct KeyPressModifier<Content: View>: View {
+    /// The content view.
+    let content: Content
+
+    /// The keys to listen for (nil = all keys).
+    let keys: Set<Key>?
+
+    /// The handler to call when a matching key is pressed.
+    /// Returns true if the event was handled, false to let it propagate.
+    let handler: (KeyEvent) -> Bool
+
+    public var body: Never {
+        fatalError("KeyPressModifier renders via Renderable")
+    }
+}
+
+// MARK: - Renderable
+
+extension KeyPressModifier: Renderable {
+    public func renderToBuffer(context: RenderContext) -> FrameBuffer {
+        // Register the key handler
+        KeyEventDispatcher.shared.addHandler { [keys, handler] event in
+            // Check if we should handle this key
+            if let allowedKeys = keys {
+                guard allowedKeys.contains(event.key) else {
+                    return false
+                }
+            }
+
+            // Call handler and return whether it consumed the event
+            return handler(event)
+        }
+
+        // Render the content
+        return TUIKit.renderToBuffer(content, context: context)
+    }
+}
+
+// MARK: - View Extension
+
+extension View {
+    /// Adds a handler for key press events.
+    ///
+    /// The handler is called when any key is pressed while this view
+    /// is in the view hierarchy. Return `true` to consume the event,
+    /// or `false` to let it propagate to other handlers.
+    ///
+    /// # Example
+    ///
+    /// ```swift
+    /// Text("Press any key")
+    ///     .onKeyPress { event in
+    ///         if event.key == .enter {
+    ///             doSomething()
+    ///             return true  // Consumed
+    ///         }
+    ///         return false  // Let others handle it
+    ///     }
+    /// ```
+    ///
+    /// - Parameter handler: The handler to call on key press. Returns true if handled.
+    /// - Returns: A view that handles key presses.
+    public func onKeyPress(_ handler: @escaping (KeyEvent) -> Bool) -> some View {
+        KeyPressModifier(content: self, keys: nil, handler: handler)
+    }
+
+    /// Adds a handler for specific key press events.
+    ///
+    /// # Example
+    ///
+    /// ```swift
+    /// Text("Use arrow keys")
+    ///     .onKeyPress(keys: [.up, .down]) { event in
+    ///         if event.key == .up {
+    ///             moveUp()
+    ///         } else {
+    ///             moveDown()
+    ///         }
+    ///         return true
+    ///     }
+    /// ```
+    ///
+    /// - Parameters:
+    ///   - keys: The keys to listen for.
+    ///   - handler: The handler to call on key press. Returns true if handled.
+    /// - Returns: A view that handles specific key presses.
+    public func onKeyPress(keys: Set<Key>, handler: @escaping (KeyEvent) -> Bool) -> KeyPressModifier<Self> {
+        KeyPressModifier(content: self, keys: keys, handler: handler)
+    }
+
+    /// Adds a handler for a single key press.
+    ///
+    /// This handler always consumes the event when the specified key is pressed.
+    ///
+    /// # Example
+    ///
+    /// ```swift
+    /// Text("Press Enter to continue")
+    ///     .onKeyPress(.enter) {
+    ///         continueAction()
+    ///     }
+    /// ```
+    ///
+    /// - Parameters:
+    ///   - key: The key to listen for.
+    ///   - action: The action to perform.
+    /// - Returns: A view that handles the specific key press.
+    public func onKeyPress(_ key: Key, action: @escaping () -> Void) -> KeyPressModifier<Self> {
+        KeyPressModifier(content: self, keys: [key], handler: { _ in
+            action()
+            return true
+        })
+    }
+}