better-LVGL-for-dsh: Offline LVGL 8.4 Knowledge Kit for dsh

When writing LVGL code with agents, the most common failure mode is the mixing of API versions. Since the model was trained on significantly more v9 content than v8.4, the generated code often mixes APIs from both versions—for instance, `lv_display_create()` (v9) and `lv_disp_drv_t` (v8) appearing in the same segment, or calling `lv_async_call()` which does not exist in v8.4 at all. For projects locked to v8.4, these issues can only be resolved through manual line-by-line debugging. DSH's philosophy is "everything is a plugin," and the skill mechanism is ideally suited to encapsulate such domain knowledge. Below, I introduce better-LVGL-for-dsh, maintained by sa998aaron.