add context window monitor

Writes the current context window to logs/current_context_window (uses a symlink to a session ID).

This PR was unfortunately generated by a different LLM and did a ton of superficial reformating, it's actually a fairly small and benign change, but I don't want to roll back everything. Hope that's ok.

crates/g3-computer-control/tests/integration_test.rs

@@ -3,29 +3,35 @@ use g3_computer_control::*;
 #[tokio::test]
 async fn test_screenshot() {
     let controller = create_controller().expect("Failed to create controller");
-    
+
     // Test that screenshot without window_id fails with appropriate error
     let path = "/tmp/test_screenshot.png";
     let result = controller.take_screenshot(path, None, None).await;
-    assert!(result.is_err(), "Expected error when window_id is not provided");
-    
+    assert!(
+        result.is_err(),
+        "Expected error when window_id is not provided"
+    );
+
     let error_msg = result.unwrap_err().to_string();
-    assert!(error_msg.contains("window_id is required"), 
-        "Expected error message about window_id being required, got: {}", error_msg);
+    assert!(
+        error_msg.contains("window_id is required"),
+        "Expected error message about window_id being required, got: {}",
+        error_msg
+    );
 }
 
 #[tokio::test]
 async fn test_screenshot_with_window() {
     let controller = create_controller().expect("Failed to create controller");
-    
+
     // Take screenshot of Finder (should always be available on macOS)
     let path = "/tmp/test_screenshot_finder.png";
     let result = controller.take_screenshot(path, None, Some("Finder")).await;
-    
+
     // This test may fail if Finder is not running, so we just check it doesn't panic
     // and returns a proper Result
     let _ = result; // Don't assert success since Finder might not be visible
-    
+
     // Clean up
     let _ = std::fs::remove_file(path);
 }