Implements FenParser.parseBoard() to parse FEN piece-placement strings
into a Board, with proper None propagation on invalid input.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

@@ -44,2 +44,4 @@
 /jacoco-reporter/.venv/
 /.claude/settings.local.json
+.metals/
+.metals/

@@ -0,0 +1,41 @@
+# 🔒 CODE FREEZE NOTICE

@@ -0,0 +218,4 @@
+          "Illegal move."
+        ))
+
+end GameEngine

@@ -0,0 +214,4 @@
+    invoker.execute(cmd3)  // While loop condition should be false, no iterations
+    invoker.history.size shouldBe 3
+
+end CommandInvokerBranchTest

@@ -0,0 +121,4 @@
+    invoker.history(1) shouldBe cmd3
+    invoker.getCurrentIndex shouldBe 1
+
+end CommandInvokerTest

@@ -0,0 +50,4 @@
+    val cmd = ResetCommand()
+    cmd.description shouldBe "Reset board"
+
+end CommandTest

@@ -0,0 +275,4 @@
+    override def onGameEvent(event: GameEvent): Unit =
+      events += event
+
+end GameEngineTest

@@ -0,0 +13,4 @@
+    val tui = new TerminalUI(engine)
+    tui.start()
+
+end Main

@@ -0,0 +74,4 @@
+    val redoHint = if engine.canRedo then " [redo]" else ""
+    print(s"${turn.label}'s turn. Enter move (or 'quit'/'q' to exit)$undoHint$redoHint: ")
+
+end TerminalUI

@@ -0,0 +1 @@
+@main def test() = println("hi")