feat(espidf): LVGL and esp_lvgl_port, the layer every official demo's UI sits on

Probed against staging the same way as the previous commit: lvgl.h and
esp_lvgl_port.h both died at "No such file or directory", so a visitor
could not paste a single screen of esp-dev-kits UI code. Declared only
when the source includes the header, so no other build pays for it.

backend/app/services/espidf_compiler.py

@@ -909,6 +909,12 @@ class ESPIDFCompiler:
         (r'iot_knob\.h', 'espressif/knob', '*'),
         (r'esp_lcd_touch_gt911\.h', 'espressif/esp_lcd_touch_gt911', '*'),
         (r'esp_codec_dev\.h', 'espressif/esp_codec_dev', '*'),
+        # LVGL and its BSP glue: every official board demo's UI is built on
+        # them, so without these a visitor cannot paste a single screen of
+        # esp-dev-kits code. The dependency is only declared when the source
+        # includes the header, so nothing else pays for the bigger build.
+        (r'lvgl\.h', 'lvgl/lvgl', '*'),
+        (r'esp_lvgl_port\.h', 'espressif/esp_lvgl_port', '*'),
     )
 
     def _detect_managed_components(self, code: str) -> dict:

test/backend/unit/test_espidf_pure_mode.py

@@ -166,6 +166,8 @@ class ManagedComponentDetectionTests(unittest.TestCase):
             '#include "esp_lcd_st77916.h"': 'espressif/esp_lcd_st77916',
             '#include "esp_lcd_touch_cst816s.h"': 'espressif/esp_lcd_touch_cst816s',
             '#include "esp_lcd_ek79007.h"': 'espressif/esp_lcd_ek79007',
+            '#include "lvgl.h"': 'lvgl/lvgl',
+            '#include "esp_lvgl_port.h"': 'espressif/esp_lvgl_port',
         }
         for line, component in cases.items():
             with self.subTest(line=line):