fix(site): handle missing default chart time (#2397)

Co-authored-by: henrygd <hank@henrygd.me>

internal/site/src/lib/stores.ts

@@ -1,4 +1,4 @@
-import { atom, computed, listenKeys, map, type ReadableAtom } from "nanostores"
+import { atom, computed, map, type ReadableAtom } from "nanostores"
 import type { AlertMap, ChartTimes, SystemRecord, UpdateInfo, UserSettings } from "@/types"
 import { pb } from "./api"
 import { Unit } from "./enums"
@@ -31,8 +31,11 @@ export const $publicKey = atom("")
 /** New version info if an update is available, otherwise undefined */
 export const $newVersion = atom<UpdateInfo | undefined>()
 
+/** Chart time period used when user settings don't provide one */
+export const defaultChartTime: ChartTimes = "1h"
+
 /** Chart time period */
-export const $chartTime = atom<ChartTimes>("1h")
+export const $chartTime = atom<ChartTimes>(defaultChartTime)
 
 /** Whether to display average or max chart values */
 export const $maxValues = atom(false)
@@ -50,13 +53,25 @@ export const $maxValues = atom(false)
 
 /** User settings */
 export const $userSettings = map<UserSettings>({
-	chartTime: "1h",
+	chartTime: defaultChartTime,
 	emails: [pb.authStore.record?.email || ""],
 	unitNet: Unit.Bytes,
 	unitTemp: Unit.Celsius,
 })
-// update chart time on change
-listenKeys($userSettings, ["chartTime"], ({ chartTime }) => $chartTime.set(chartTime))
+
+/** Chart time period stored in user settings, or the default if it's missing */
+export function getUserChartTime(settings: UserSettings = $userSettings.get()): ChartTimes {
+	return settings.chartTime || defaultChartTime
+}
+
+/**
+ * Apply settings loaded from the database, including the default chart time.
+ * Other settings writes don't touch $chartTime so they can't reset the active chart range.
+ */
+export function hydrateUserSettings(settings: UserSettings) {
+	$userSettings.set(settings)
+	$chartTime.set(getUserChartTime(settings))
+}
 
 /** Container chart filter */
 export const $containerFilter = atom("")