✨ feat: implement build version check and update build info handling

frontend/src/lib/store.ts

@@ -50,40 +50,22 @@ const publishLocation = (_p?: string) => {
 }
 
 if (typeof history !== "undefined") {
-    if (typeof Proxy !== "undefined") {
-        // modern browser
-        const historyApply = (
-            target: (this: any, ...args: readonly any[]) => unknown,
-            thisArg: any,
-            argumentsList: string | readonly any[]
-        ) => {
-            publishLocation(argumentsList && argumentsList.length >= 2 && argumentsList[2])
-            Reflect.apply(target, thisArg, argumentsList)
-        }
-
-        history.pushState = new Proxy(history.pushState, {
-            apply: historyApply,
-        })
-
-        history.replaceState = new Proxy(history.replaceState, {
-            apply: historyApply,
-        })
-    } else {
-        // ie11
-        const pushStateFn = history.pushState
-        const replaceStateFn = history.replaceState
-
-        history.pushState = function (data: any, title: string, url?: string) {
-            publishLocation(url)
-            // @ts-ignore
-            return pushStateFn.apply(history, arguments)
-        }
-        history.replaceState = function (data: any, title: string, url?: string) {
-            publishLocation(url)
-            // @ts-ignore
-            return replaceStateFn.apply(history, arguments)
-        }
+    const historyApply = (
+        target: (this: any, ...args: readonly any[]) => unknown,
+        thisArg: any,
+        argumentsList: string | readonly any[]
+    ) => {
+        publishLocation(argumentsList && argumentsList.length >= 2 && argumentsList[2])
+        Reflect.apply(target, thisArg, argumentsList)
     }
+
+    history.pushState = new Proxy(history.pushState, {
+        apply: historyApply,
+    })
+
+    history.replaceState = new Proxy(history.replaceState, {
+        apply: historyApply,
+    })
 } // else ssr -> no history handling
 
 typeof window !== "undefined" &&

frontend/src/lib/versionCheck.ts

@@ -0,0 +1,54 @@
+/**
+ * Build-Version-Check: Auto-Reload when a newer build is detected on the server
+ *
+ * Every GET API response includes the header X-Build-Time with the server's build
+ * timestamp. If it's newer than the one embedded in the frontend bundle, a toast
+ * is shown and the page is automatically reloaded after a short delay.
+ */
+import { buildTime } from "./buildInfo"
+import { addToast } from "./toast"
+
+/** Prevents multiple triggers within the same page session */
+let triggered = false
+
+const RELOAD_DELAY_MS = 3000
+const STORAGE_KEY = "__build_reload__"
+
+/**
+ * Checks whether the server has a newer build than the current frontend bundle.
+ * Only runs in the browser (SSR-safe).
+ *
+ * @param serverBuildTime - ISO timestamp from the X-Build-Time response header
+ */
+export function checkBuildVersion(serverBuildTime: string | null | undefined): void {
+    if (!serverBuildTime || typeof window === "undefined") return
+    if (triggered) return
+
+    // Only react if the server build is actually newer
+    if (serverBuildTime <= buildTime) return
+
+    // Loop protection: if we already reloaded for this exact build, don't reload again
+    // (e.g. CDN/cache still serving old bundle)
+    try {
+        if (sessionStorage.getItem(STORAGE_KEY) === serverBuildTime) return
+    } catch (_) {
+        // sessionStorage not available (e.g. privacy mode) – continue anyway
+    }
+
+    triggered = true
+
+    // Show toast notification
+    addToast("New version available – page will refresh…", "info", RELOAD_DELAY_MS + 2000)
+
+    // Remember that we're reloading for this build timestamp
+    try {
+        sessionStorage.setItem(STORAGE_KEY, serverBuildTime)
+    } catch (_) {
+        // ignore
+    }
+
+    // Auto-reload after short delay so toast is visible
+    setTimeout(() => {
+        window.location.reload()
+    }, RELOAD_DELAY_MS)
+}