Fix signal handler deadlock and add satellite TLE data

Remove logging and cleanup_all_processes() from signal handler to
prevent deadlocks when another thread holds the logging or process lock.
Process cleanup is handled by the atexit handler instead.

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

utils/process.py

@@ -85,11 +85,13 @@ atexit.register(cleanup_all_processes)
 
 # Handle signals for graceful shutdown
 def _signal_handler(signum, frame):
-    """Handle termination signals."""
+    """Handle termination signals.
+
+    Keep this minimal — logging and lock acquisition in signal handlers
+    can deadlock when another thread holds the logging or process lock.
+    Process cleanup is handled by the atexit handler registered above.
+    """
     import sys
-    logger.info(f"Received signal {signum}, cleaning up...")
-    cleanup_all_processes()
-    # Re-raise KeyboardInterrupt for SIGINT so Flask can handle shutdown
     if signum == signal.SIGINT:
         raise KeyboardInterrupt()
     sys.exit(0)