fix: convert dial Fahrenheit input to Celsius before climate.control

The dual-arc setpoint dial uses a Fahrenheit-range scale (60-90) to
match the Lennox reference UI, but climate.control expects Celsius
throughout this codebase. Dragging the dial was sending raw
Fahrenheit values straight into target_temperature_low/high, which
would have commanded wildly wrong setpoints on live hardware.
Also fixes a stale comment pointing at the wrong file after the
panel.yaml extraction.

firmware/components/display-classic.yaml

@@ -108,7 +108,7 @@ lvgl:
               then:
                 - climate.control:
                     id: main_thermostat
-                    target_temperature_low: !lambda "return x;"
+                    target_temperature_low: !lambda "return (x - 32.0f) * 5.0f / 9.0f;"
                 - lvgl.label.update:
                     id: heat_to_value_label
                     text:
@@ -138,7 +138,7 @@ lvgl:
               then:
                 - climate.control:
                     id: main_thermostat
-                    target_temperature_high: !lambda "return x;"
+                    target_temperature_high: !lambda "return (x - 32.0f) * 5.0f / 9.0f;"
                 - lvgl.label.update:
                     id: cool_to_value_label
                     text:

firmware/components/sensors.yaml

@@ -1,6 +1,6 @@
 sensor:
   - platform: bme280_i2c
-    i2c_id: i2c_bus         # shared bus declared in display.yaml — GPIO8 SDA / GPIO9 SCL
+    i2c_id: i2c_bus         # shared bus declared in panel.yaml — GPIO8 SDA / GPIO9 SCL
     address: 0x76            # BME280 default; try 0x77 if SDO is pulled high
     update_interval: 30s
     temperature: