Fix all ruff linting errors

- Fix import ordering (isort)
- Remove unused imports
- Fix line too long (>100 chars)
- Fix variable naming (PIECES -> piece_chars)
- Fix bare except clause
- Remove unused variable

tests/test_ssh_server.py

@@ -1,9 +1,9 @@
 """Tests for SSH server functionality."""
 
-import asyncio
-import pytest
 from unittest.mock import AsyncMock, MagicMock, patch
 
+import pytest
+
 
 class TestShellMateSSHServer:
     """Test SSH server authentication."""
@@ -113,9 +113,10 @@ class TestChessBoard:
 
     def test_board_initialization(self):
         """Board should initialize with standard position."""
-        from shellmate.tui.widgets.board import ChessBoardWidget
         import chess
 
+        from shellmate.tui.widgets.board import ChessBoardWidget
+
         widget = ChessBoardWidget()
 
         assert widget.board.fen() == chess.STARTING_FEN
@@ -136,9 +137,10 @@ class TestChessBoard:
 
     def test_square_selection(self):
         """Selecting a square should show legal moves."""
-        from shellmate.tui.widgets.board import ChessBoardWidget
         import chess
 
+        from shellmate.tui.widgets.board import ChessBoardWidget
+
         widget = ChessBoardWidget()
 
         # Select e2 pawn
@@ -152,9 +154,10 @@ class TestChessBoard:
 
     def test_square_deselection(self):
         """Deselecting should clear legal moves."""
-        from shellmate.tui.widgets.board import ChessBoardWidget
         import chess
 
+        from shellmate.tui.widgets.board import ChessBoardWidget
+
         widget = ChessBoardWidget()
         widget.select_square(chess.E2)
         widget.select_square(None)
@@ -251,9 +254,10 @@ class TestIntegration:
     @pytest.mark.asyncio
     async def test_server_starts(self):
         """Server should start without errors."""
-        from shellmate.ssh.server import start_server
-        import tempfile
         import os
+        import tempfile
+
+        from shellmate.ssh.server import start_server
 
         # Create a temporary host key
         with tempfile.TemporaryDirectory() as tmpdir:

tests/test_ui_render.py

@@ -1,20 +1,22 @@
 """Tests for UI rendering - catches Rich markup errors before deployment."""
 
-import pytest
 from io import StringIO
+
+from rich.align import Align
+from rich.box import ROUNDED
 from rich.console import Console
 from rich.panel import Panel
 from rich.table import Table
 from rich.text import Text
-from rich.align import Align
-from rich.box import ROUNDED
 
 
 def test_menu_render_no_markup_errors():
     """Test that the main menu renders without Rich markup errors."""
     # Simulate the menu rendering code
     output = StringIO()
-    console = Console(file=output, width=80, height=24, force_terminal=True, color_system="truecolor")
+    console = Console(
+        file=output, width=80, height=24, force_terminal=True, color_system="truecolor"
+    )
 
     username = "testuser"
     width = 80
@@ -35,10 +37,18 @@ def test_menu_render_no_markup_errors():
     menu_table.add_column(justify="center")
     menu_table.add_row(Text(f"Welcome, {username}!", style="cyan"))
     menu_table.add_row("")
-    menu_table.add_row("[bright_white on blue] 1 [/bright_white on blue]  Play vs AI       [dim]♔ vs ♚[/dim]")
-    menu_table.add_row("[bright_white on magenta] 2 [/bright_white on magenta]  Play vs Human   [dim]♔ vs ♔[/dim]")
-    menu_table.add_row("[bright_white on green] 3 [/bright_white on green]  Learn & Practice [dim]📖[/dim]")
-    menu_table.add_row("[bright_white on red] q [/bright_white on red]  Quit             [dim]👋[/dim]")
+    menu_table.add_row(
+        "[bright_white on blue] 1 [/]  Play vs AI       [dim]♔ vs ♚[/dim]"
+    )
+    menu_table.add_row(
+        "[bright_white on magenta] 2 [/]  Play vs Human   [dim]♔ vs ♔[/dim]"
+    )
+    menu_table.add_row(
+        "[bright_white on green] 3 [/]  Learn & Practice [dim]📖[/dim]"
+    )
+    menu_table.add_row(
+        "[bright_white on red] q [/]  Quit             [dim]👋[/dim]"
+    )
     menu_table.add_row("")
     menu_table.add_row(Text("Press a key to select...", style="dim italic"))
 
@@ -93,7 +103,7 @@ def test_chess_board_render():
     """Test that chess board renders without errors."""
     output = StringIO()
 
-    PIECES = {
+    piece_map = {
         'K': '♔', 'Q': '♕', 'R': '♖', 'B': '♗', 'N': '♘', 'P': '♙',
         'k': '♚', 'q': '♛', 'r': '♜', 'b': '♝', 'n': '♞', 'p': '♟',
     }
@@ -106,8 +116,8 @@ def test_chess_board_render():
     # 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, '?')
+    for piece_char in pieces_row:
+        char = piece_map.get(piece_char, '?')
         row += f" {char} |"
     row += " 8"
     lines.append(row)