feat v1.26.0: state-reflecting icons + 'value instead of an icon' display (issue #3)

- stateIcon(): door/window/garage open-closed, lock locked-unlocked, bulb on;
  custom icons and unavailable/unknown never morph; gated by live_states
- marker display 'value': the measurement (with unit) is the marker body,
  corner badges hidden; numeric fallback chain temp - hum - primary state
- TESTING.md rows, smoke_state_value.mjs, +1 unit test

src/i18n/en.json

@@ -242,5 +242,6 @@
   "gs.light_none": "No light sources",
   "mode.view": "View",
   "mode.plan": "Plan",
-  "mode.devices": "Devices"
+  "mode.devices": "Devices",
+  "display.value": "Value instead of an icon"
 }