feat: add LVGL base config with persistent bottom nav bar

firmware/components/display.yaml

@@ -37,11 +37,78 @@ display:
         number: 6              # EXIO6 = LCD_VDD_EN (VCOM enable) — the built-in preset doesn't set
                                  # this, but the Waveshare wiki confirms VCOM must be driven high on
                                  # this board or the panel won't display correctly. Added explicitly.
-    lambda: |-
-      it.fill(Color::BLACK);
-      it.print(512, 300, id(font_label), TextAlign::CENTER, "Thermostat — Phase 1 OK");
 
-font:
-  - file: "gfonts://Roboto"
-    id: font_label
-    size: 32
+lvgl:
+  id: lvgl_comp
+  displays:
+    - lcd_display
+  touchscreens:
+    - touch_gt911
+  pages:
+    - id: page_home
+      widgets: []
+    - id: page_sensors
+      widgets: []
+    - id: page_settings
+      widgets: []
+    - id: page_schedule
+      widgets: []
+  top_layer:
+    widgets:
+      - obj:
+          id: nav_bar
+          align: bottom_mid
+          width: 100%
+          height: 90px
+          pad_all: 4
+          radius: 0
+          border_width: 0
+          outline_width: 0
+          scrollable: false
+          layout:
+            type: flex
+            flex_flow: row
+            flex_align_cross: center
+            flex_align_track: center
+            flex_align_main: space_evenly
+          widgets:
+            - button:
+                id: nav_btn_home
+                width: 220px
+                height: 78px
+                on_click:
+                  lvgl.page.show: page_home
+                widgets:
+                  - label:
+                      text: "Home"
+                      text_font: montserrat_20
+            - button:
+                id: nav_btn_sensors
+                width: 220px
+                height: 78px
+                on_click:
+                  lvgl.page.show: page_sensors
+                widgets:
+                  - label:
+                      text: "Sensors"
+                      text_font: montserrat_20
+            - button:
+                id: nav_btn_settings
+                width: 220px
+                height: 78px
+                on_click:
+                  lvgl.page.show: page_settings
+                widgets:
+                  - label:
+                      text: "Settings"
+                      text_font: montserrat_20
+            - button:
+                id: nav_btn_schedule
+                width: 220px
+                height: 78px
+                on_click:
+                  lvgl.page.show: page_schedule
+                widgets:
+                  - label:
+                      text: "Schedule"
+                      text_font: montserrat_20