v1.4.0: digit-only flaps with white euro text, nixie white euro + configurable flicker, mode-conditional config fields; fix stale derived-property reads in change handler

README.md

@@ -10,8 +10,8 @@ Three display styles, configurable in the settings dialog:
 | Style | Description |
 |---|---|
 | *Plain text* | Trend-colored text (green/red/grey) |
-| *Split-flap board* | Airport board: white characters on black flaps, cascading flip animation on price changes, trend LED |
-| *Nixie tubes* | Retro amber glowing digits in glass tubes (with a soft flicker), trend LED |
+| *Split-flap board* | Airport board: white digit flaps, white € sign in the default font, cascading flip animation on price changes (configurable duration), trend LED |
+| *Nixie tubes* | Retro amber glowing digits in glass tubes with configurable random flicker, white € sign in the default font, trend LED |
 
 In the split-flap and nixie styles the digits keep their display color and the
 trend (up/down/unchanged) is shown on a small LED next to the display.
@@ -35,7 +35,10 @@ representations.
   5 minutes. A hint text in the config dialog explains this.
 - **Split-flap cascade (seconds)** — default 3, range 1–15. Spreads the flip
   animation of a price change evenly over this many seconds (applies to the
-  split-flap display style).
+  split-flap display style). Only shown when that style is selected.
+- **Nixie flicker (0 = off)** — default 40, range 0–100. Random cathode-dropout
+  flicker of the nixie tubes; 0 disables it, higher values flicker more often
+  and deeper. Only shown when the nixie style is selected.
 
 Configurable via right-click on the widget → *Configure Bitcoin Price…* → *General*.