fix: system theme selection immediately applies OS preference instead of reverting to light

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.20.27] - 2026-04-20
+
+### Fixed
+- Selecting "System" theme in settings now immediately applies the OS dark/light preference instead of reverting to light mode until the next page reload
+
 ## [0.20.26] - 2026-04-20
 
 ### Added

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "oikos",
-  "version": "0.20.26",
+  "version": "0.20.27",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "oikos",
-      "version": "0.20.26",
+      "version": "0.20.27",
       "license": "MIT",
       "dependencies": {
         "bcrypt": "^6.0.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "oikos",
-  "version": "0.20.26",
+  "version": "0.20.27",
   "description": "Self-hosted family planner - calendar, tasks, shopping, meal planning, budget and more. Private, open-source, no subscription.",
   "main": "server/index.js",
   "type": "module",

public/pages/settings.js

@@ -854,7 +854,8 @@ function applyTheme(value) {
   if (value === 'light' || value === 'dark') {
     document.documentElement.setAttribute('data-theme', value);
   } else {
-    document.documentElement.removeAttribute('data-theme');
+    const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+    document.documentElement.setAttribute('data-theme', prefersDark ? 'dark' : 'light');
   }
 }