Simplify chess board rendering - plain text that works over SSH

- Remove complex Rich styling from board (caused rendering issues)
- Use simple ASCII box drawing (+---+) instead of Unicode box chars
- Use dots for dark squares, spaces for light
- Plain text status display
- Much more reliable over SSH terminals

tests/test_ui_render.py

@@ -92,36 +92,34 @@ def test_game_status_render():
 def test_chess_board_render():
     """Test that chess board renders without errors."""
     output = StringIO()
-    console = Console(file=output, width=80, height=24, force_terminal=True, color_system="truecolor")
     
     PIECES = {
         'K': '♔', 'Q': '♕', 'R': '♖', 'B': '♗', 'N': '♘', 'P': '♙',
         'k': '♚', 'q': '♛', 'r': '♜', 'b': '♝', 'n': '♞', 'p': '♟',
     }
     
-    # Render a simple board section
-    console.print("    a   b   c   d   e   f   g   h")
-    console.print("  ┌───┬───┬───┬───┬───┬───┬───┬───┐")
-    
-    # Render one rank with colored squares
-    row = "8 │"
-    for file in range(8):
-        is_light = (7 + file) % 2 == 1
-        if is_light:
-            bg = "on #769656"
-        else:
-            bg = "on #4a7c3f"
-        
-        # Starting position pieces
-        pieces_row = ['r', 'n', 'b', 'q', 'k', 'b', 'n', 'r']
-        char = PIECES.get(pieces_row[file], ' ')
-        row += f"[#1a1a1a bold {bg}] {char} [/]│"
+    # Simplified board rendering (plain text)
+    lines = []
+    lines.append("      a   b   c   d   e   f   g   h")
+    lines.append("    +---+---+---+---+---+---+---+---+")
     
+    # Render rank 8 with pieces
+    pieces_row = ['r', 'n', 'b', 'q', 'k', 'b', 'n', 'r']
+    row = "  8 |"
+    for file, piece_char in enumerate(pieces_row):
+        char = PIECES.get(piece_char, '?')
+        row += f" {char} |"
     row += " 8"
-    console.print(row)
+    lines.append(row)
+    lines.append("    +---+---+---+---+---+---+---+---+")
+    
+    for line in lines:
+        output.write(line + "\n")
     
     rendered = output.getvalue()
     assert "a   b   c" in rendered
+    assert "♜" in rendered  # Black rook
+    assert "+---+" in rendered
 
 
 def test_narrow_terminal_render():