fix: mark base_url as unsaved when using browser fallback (#7964)

* fix: mark base_url as unsaved when using browser fallback in instance settings

When base_url is not set in the database, the frontend silently fills in
window.location.origin but also snapshots it as the initial value. This
makes the dirty-check see no change, so the Save button stays disabled
and the user cannot persist the auto-detected value.

Fix by snapshotting initialValues before applying the fallback, and show
a yellow warning indicating the value is auto-detected and unsaved.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: render base_url fallback warning inside the setting card

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: centdix

frontend/src/lib/components/InstanceSetting.svelte

@@ -35,9 +35,10 @@
 		loading?: boolean
 		openSmtpSettings?: () => void
 		oauths?: Record<string, any>
+		warning?: string
 	}
 
-	let { setting, version, values, loading = true, openSmtpSettings, oauths }: Props = $props()
+	let { setting, version, values, loading = true, openSmtpSettings, oauths, warning }: Props = $props()
 	const dispatch = createEventDispatcher()
 
 	let latestKeyRenewalAttempt: {
@@ -282,6 +283,11 @@
 						bind:value={$values[setting.key]}
 						class="max-w-lg"
 					/>
+					{#if warning}
+						<span class="text-yellow-600 dark:text-yellow-500 text-2xs">
+							{warning}
+						</span>
+					{/if}
 					{#if setting.advancedToggle}
 						<div class="mt-1">
 							<Toggle

frontend/src/lib/components/InstanceSettings.svelte

@@ -52,6 +52,7 @@
 	let requirePreexistingUserForOauth: boolean = $state(false)
 
 	let initialValues: Record<string, any> = $state({})
+	let baseUrlIsFallback = $state(false)
 	let snowflakeAccountIdentifier = $state('')
 	let version: string = $state('')
 	let loading = $state(true)
@@ -96,16 +97,20 @@
 
 		let nvalues: Record<string, any> = { ...gs }
 
-		if (!nvalues['base_url']) {
-			nvalues['base_url'] = window.location.origin
-		}
+		baseUrlIsFallback = !nvalues['base_url']
 		if (nvalues['retention_period_secs'] == undefined) {
 			nvalues['retention_period_secs'] = 60 * 60 * 24 * 30
 		}
 		applyFormDefaults(nvalues)
 
+		// Snapshot initialValues before applying the base_url fallback so that
+		// the dirty-check detects the unsaved default and enables the Save button.
+		initialValues = JSON.parse(JSON.stringify(nvalues))
+
+		if (baseUrlIsFallback) {
+			nvalues['base_url'] = window.location.origin
+		}
 		$values = nvalues
-		initialValues = JSON.parse(JSON.stringify($values))
 		loading = false
 
 		// populate snowflake account identifier from db
@@ -186,6 +191,7 @@
 			initialValues = JSON.parse(JSON.stringify($values))
 			initialOauths = JSON.parse(JSON.stringify(oauths))
 			initialRequirePreexistingUserForOauth = requirePreexistingUserForOauth
+			baseUrlIsFallback = false
 
 			if (licenseKeySet) {
 				setLicense()
@@ -502,6 +508,9 @@
 			const v = $values[s.key]
 			initialValues[s.key] = v !== undefined ? JSON.parse(JSON.stringify(v)) : undefined
 		}
+		if (categorySettings.some((s) => s.key === 'base_url')) {
+			baseUrlIsFallback = false
+		}
 
 		// Handle Auth/OAuth/SAML-specific saves
 		if (category === 'Auth/OAuth/SAML') {
@@ -998,6 +1007,7 @@
 						{values}
 						{version}
 						{oauths}
+						warning={setting.key === 'base_url' && baseUrlIsFallback ? 'Auto-detected from browser — not yet saved' : undefined}
 					/>
 				{/if}
 			{/each}