hardware: retire dashboard uart and assign oled pins

tests/test_http_api_contract.py

@@ -425,3 +425,26 @@ def test_cargo_oled_shows_setup_and_service_pages():
     assert 'oledClear("Alarms")' in source
     assert "oledShowSetupPage();" in source
     assert "oledLoop();" in source
+
+
+def test_gpio_pin_plan_assigns_oled_to_21_22():
+    config = (ROOT / "firmware" / "esp32" / "overland-controller" / "config.h").read_text()
+    source = firmware_source()
+
+    assert "#define OLED_I2C_SDA_PIN 21" in config
+    assert "#define OLED_I2C_SCL_PIN 22" in config
+    assert "#define OLED_SETUP_BUTTON_PIN 25" in config
+    assert "const int OLED_I2C_SDA = OLED_I2C_SDA_PIN;" in source
+    assert "const int OLED_I2C_SCL = OLED_I2C_SCL_PIN;" in source
+    assert "const int OLED_BUTTON_PIN = OLED_SETUP_BUTTON_PIN;" in source
+
+
+def test_legacy_dashboard_uart_is_disabled_by_default():
+    config = (ROOT / "firmware" / "esp32" / "overland-controller" / "config.h").read_text()
+    source = firmware_source()
+
+    assert "#define DASHBOARD_UART_ENABLED 0" in config
+    assert "DASHBOARD_UART_TX_PIN 21" not in config
+    assert "DASHBOARD_UART_RX_PIN 22" not in config
+    assert "#if DASHBOARD_UART_ENABLED" in source
+    assert "pollDashboardUart();" in source