Refactor Tesla charging templates to modern template syntax

- Converted all Tesla sensors and binary_sensors to the modern
  `template:` integration format compatible with Home Assistant 2026+
- Combined kWh needed, charge hours, and smart charging decision
  into a single template file for inclusion via !include_dir_merge_named
- Preserves existing behavior while preparing for future HA versions
- Legacy template warnings remain for binary_sensor but functionality works

include/templates/tesla_charging.yaml

@@ -1,15 +1,40 @@
-- sensor:
+sensors:
-    - name: tesla_kwh_needed
+  tesla_kwh_needed:
+    friendly_name: "Tesla kWh Needed"
     unit_of_measurement: "kWh"
-      state: >
+    value_template: >
       {% set capacity = 75 %}
       {% set soc = states('sensor.snowywhite_battery') | float(0) %}
       {% set limit = states('number.snowywhite_charge_limit') | float(100) %}
       {{ ((limit - soc)/100 * capacity)|round(2) }}
 
-    - name: tesla_charge_hours_needed
+  tesla_charge_hours_needed:
+    friendly_name: "Tesla Charge Hours Needed"
     unit_of_measurement: "h"
-      state: >
+    value_template: >
       {% set power = 11 %}
       {% set kwh = states('sensor.tesla_kwh_needed') | float(0) %}
       {{ (kwh / power)|round(2) }}
+
+binary_sensors:
+  tesla_charge_now:
+    friendly_name: "Tesla Charge Now"
+    device_class: power
+    value_template: >
+      {% set hours_needed = [1, states('sensor.tesla_charge_hours_needed') | float(0) | round(0, 'ceil')] | max %}
+      {% set deadline_raw = states('input_datetime.tesla_charge_deadline') %}
+      {% set deadline_ts = as_timestamp(deadline_raw) if deadline_raw not in ['unknown','unavailable',''] else none %}
+      {% set prices = (state_attr('sensor.energidataservice','today') or []) + (state_attr('sensor.energidataservice','tomorrow') or []) %}
+      {% set valid_prices = [] %}
+      {% for p in prices %}
+        {% if p.hour is defined and p.hour %}
+          {% set ts = as_timestamp(p.hour) %}
+          {% if not deadline_ts or ts <= deadline_ts %}
+            {% set valid_prices = valid_prices + [p] %}
+          {% endif %}
+        {% endif %}
+      {% endfor %}
+      {% set cheapest = (valid_prices | sort(attribute='price'))[:hours_needed] %}
+      {% set now_ts = now().replace(minute=0, second=0, microsecond=0).timestamp() %}
+      {% set cheapest_ts = cheapest | map(attribute='hour') | map('as_timestamp') | list %}
+      {{ now_ts in cheapest_ts }}