fix: resolve all ruff linting errors

Fixed 42 linting errors across codebase:
- Auto-fixed 35 import sorting issues (I001)
- Added unused imports to __all__ in execution/__init__.py
- Removed unused variable assignments (F841)
- Updated pyproject.toml to use [tool.ruff.lint] section

All ruff checks now pass successfully.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

tests/unit/test_cli_install.py

@@ -4,8 +4,6 @@ Unit tests for CLI install command
 Tests the command installation functionality.
 """
 
-import pytest
-from pathlib import Path
 from superclaude.cli.install_commands import (
     install_commands,
     list_available_commands,
@@ -172,7 +170,6 @@ def test_cli_integration():
     This tests that the CLI main.py can successfully import the functions
     """
     from superclaude.cli.install_commands import (
-        install_commands,
         list_available_commands,
     )
 

tests/unit/test_confidence.py

@@ -5,6 +5,7 @@ Tests pre-execution confidence assessment functionality.
 """
 
 import pytest
+
 from superclaude.pm_agent.confidence import ConfidenceChecker
 
 

tests/unit/test_reflexion.py

@@ -5,6 +5,7 @@ Tests error learning and prevention functionality.
 """
 
 import pytest
+
 from superclaude.pm_agent.reflexion import ReflexionPattern
 
 
@@ -165,7 +166,7 @@ def test_reflexion_with_real_exception():
 
     try:
         # Simulate an operation that fails
-        result = 10 / 0
+        _ = 10 / 0  # noqa: F841
     except ZeroDivisionError as e:
         # Record the error
         error_info = {

tests/unit/test_self_check.py

@@ -5,6 +5,7 @@ Tests post-implementation validation functionality.
 """
 
 import pytest
+
 from superclaude.pm_agent.self_check import SelfCheckProtocol
 
 

tests/unit/test_token_budget.py

@@ -5,6 +5,7 @@ Tests token budget allocation and management functionality.
 """
 
 import pytest
+
 from superclaude.pm_agent.token_budget import TokenBudgetManager