Update VERSION.md for firmware 6.1.1 release

Updated version information for firmware 6.1.1, including fixes for price markers and daily average calculations.

VERSION.md

@@ -2,6 +2,25 @@
 
 ## Current firmware
 
+- **Version:** 6.1.1  
+- **Release date:** 2026-03-07  
+- **Target MCU:** Seeed XIAO ESP32‑C3  
+- **Display:** 20x4 I²C LCD (PCF8574, default address `0x27`)  
+- **API endpoint:** `https://api.energy-charts.info/price?bzn=SI`  
+- **Resolution:** 15‑minute intervals, hourly averages for overview  
+
+## Highlights of v6.1.1
+
+- Fix: daily **lowest/highest hourly price marker** now includes **negative** and **0.0** prices.
+- Fix: daily average is computed over the number of valid hours (instead of always dividing by 24 even when hours were skipped).
+
+For full details, see:
+
+- [CHANGELOG.md](./CHANGELOG.md)
+- [README.md](./README.md)
+
+## Previous firmware
+
 - **Version:** 6.0.0  
 - **Release date:** 2026-01-27  
 - **Target MCU:** Seeed XIAO ESP32‑C3  
@@ -19,8 +38,3 @@
   - Then top‑of‑hour retries until successful.
 - Prevents yesterday’s prices from ever being shown as today’s.
 - Secondary info menu extended with **NVS status** and clear version label.
-
-For full details, see:
-
-- [CHANGELOG.md](./CHANGELOG.md)
-- [README.md](./README.md)