chore: clean up unused imports and sort import blocks

Remove unused imports and organize import statements to pass ruff
linting checks:

- mcp_server/feature_mcp.py: Remove unused imports (are_dependencies_satisfied,
  get_blocking_dependencies) and alphabetize import block
- parallel_orchestrator.py: Remove unused imports (time, Awaitable) and
  add blank lines between import groups per PEP 8
- server/routers/features.py: Alphabetize imports in dependency resolver

These changes were identified by running `ruff check .` and auto-fixed
with `--fix` flag.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

parallel_orchestrator.py

@@ -15,9 +15,8 @@ import os
 import subprocess
 import sys
 import threading
-import time
 from pathlib import Path
-from typing import Callable, Awaitable
+from typing import Callable
 
 import psutil
 
@@ -499,7 +498,9 @@ async def run_parallel_orchestrator(
 def main():
     """Main entry point for parallel orchestration."""
     import argparse
+
     from dotenv import load_dotenv
+
     from registry import DEFAULT_MODEL, get_project_path
 
     load_dotenv()