fix: convert AI tests from skip statements to build tags (#1783)

* fix: convert AI tests from skip statements to build tags

- Add //go:build localtest tag to uixt/ai/ai_test.go and examples/game/llk/main_test.go
- Remove environment-based skip statements and hasRequiredEnvVars functions
- Maintain consistency with existing build tag approach for mobile/device tests
- Prevents CI/CD failures when external AI services are not available

Co-authored-by: debugtalk <debugtalk@users.noreply.github.com>

* fix: add missing BoundBox type and field to Element struct

- Add BoundBox struct with X, Y, Width, Height fields
- Update Element struct to include BoundBox field
- Fix structural mismatch between test expectations and Go code
- Resolves CI compilation failures

Co-authored-by: debugtalk <debugtalk@users.noreply.github.com>

---------

Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>

examples/game/llk/main.go

@@ -34,6 +34,15 @@ type Dimensions struct {
 type Element struct {
 	Type     string   `json:"type"`     // Element type/name
 	Position Position `json:"position"` // Position in grid
+	BoundBox BoundBox `json:"boundBox"` // Bounding box coordinates
+}
+
+// BoundBox represents bounding box coordinates
+type BoundBox struct {
+	X      float64 `json:"x"`      // X coordinate
+	Y      float64 `json:"y"`      // Y coordinate
+	Width  float64 `json:"width"`  // Box width
+	Height float64 `json:"height"` // Box height
 }
 
 // Position represents grid position