fix: seed runs page filter defaults through the url so they survive sync (#11005)

Claude-Session: https://claude.ai/code/session_017KKZCLrTrWAqSeGjTzVtP2

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/FilterSearchbar.svelte

@@ -112,17 +112,37 @@
 	}
 
 	/**
-	 * Creates a URL-synced filter instance that automatically syncs with URL search parameters
+	 * Creates a URL-synced filter instance that automatically syncs with URL search parameters.
+	 *
+	 * `initial` supplies defaults for keys the URL doesn't carry (a route segment, a persisted
+	 * toggle); the returned `seed` re-applies them after a navigation has rewritten the query.
 	 */
 	export function useUrlSyncedFilterInstance<T extends FilterSchemaRec>(
-		schemaRec: T
-	): { val: Partial<FilterInstanceRec<T>> } {
+		schemaRec: T,
+		initial?: Partial<FilterInstanceRec<T>>
+	): {
+		val: Partial<FilterInstanceRec<T>>
+		seed: (values: Partial<FilterInstanceRec<T>>) => void
+	} {
 		// Build the Zod schema from the filter schema
 		const zodSchema = filterSchemaRecToZodSchema(schemaRec)
 
 		// Create URL-synced search params
 		const urlFilter = useSearchParams(zodSchema) as Record<string, unknown>
 
+		// A default has to arrive as a URL param: the URL→instance effect below drops whatever the
+		// URL lacks, so a value written to the instance is undone on the next sync. Going through
+		// urlFilter rather than straight to history keeps the search-param cells in step, so it
+		// does not matter whether a popstate follows.
+		function seed(values: Partial<FilterInstanceRec<T>>) {
+			const sp = new URLSearchParams(window.location.search)
+			for (const [key, value] of Object.entries(values) as [string, unknown][]) {
+				if (value === undefined || value === null || sp.has(key)) continue
+				urlFilter[key] = value instanceof Date ? value.toISOString() : value
+			}
+		}
+		if (initial) seed(initial)
+
 		// Create the filter instance object
 		const filterInstance: { val: Partial<FilterInstanceRec<T>> } = $state({ val: {} })
 
@@ -173,7 +193,15 @@
 			})
 		}
 
-		return filterInstance
+		return {
+			get val() {
+				return filterInstance.val
+			},
+			set val(v: Partial<FilterInstanceRec<T>>) {
+				filterInstance.val = v
+			},
+			seed
+		}
 	}
 
 	function filterToText<F extends FilterSchema>(filter: FilterInstance<F>, schema: F): string {

frontend/src/lib/components/RunsPage.svelte

@@ -84,6 +84,8 @@
 		initialPath?: string
 	}
 
+	let { initialPath }: Props = $props()
+
 	let paths: string[] = $state([])
 	let usernames: string[] = $state([])
 	let folders: string[] = $state([])
@@ -100,25 +102,30 @@
 	let perPage = useLocalStorageValue('runs_per_page', 1000, 'number')
 	let showSchedulesStorage = useLocalStorageValue('runs_show_schedules', true, 'boolean')
 	let showFutureJobsStorage = useLocalStorageValue('runs_show_future_jobs', true, 'boolean')
-	let filters = useUrlSyncedFilterInstance(untrack(() => runsFilterSearchbarSchema))
+	function filterSeeds() {
+		return {
+			path: initialPath || undefined,
+			job_trigger_kind: showSchedulesStorage.val === false ? ('!schedule' as const) : undefined,
+			show_future_jobs: showFutureJobsStorage.val === false ? false : undefined
+		}
+	}
 
-	let { initialPath }: Props = $props()
+	let filters = useUrlSyncedFilterInstance(
+		untrack(() => runsFilterSearchbarSchema),
+		untrack(filterSeeds)
+	)
+
+	// `runs/[...path]` is a single route, so a navigation between its URLs — the sidebar's own
+	// "Runs" entry, `/runs/<path>` → `/runs`, Back — rewrites the query without remounting, and
+	// what was seeded at mount is gone. Re-apply it. Editing a filter writes with `replaceState`,
+	// which never reaches `page.url`, so a filter the user clears stays cleared.
+	$effect(() => {
+		page.url.href
+		untrack(() => filters.seed(filterSeeds()))
+	})
 
 	let batchRerunOptionsIsOpen = $state(false)
 
-	// Initialize path filter from route param if provided and not already set via query params
-	if (untrack(() => initialPath) && !filters.val.path) {
-		filters.val.path = untrack(() => initialPath)
-	}
-
-	// Apply persistent toggle values from local storage if URL doesn't specify them
-	if (!page.url.searchParams.has('job_trigger_kind') && showSchedulesStorage.val === false) {
-		filters.val.job_trigger_kind = '!schedule'
-	}
-	if (!page.url.searchParams.has('show_future_jobs') && showFutureJobsStorage.val === false) {
-		filters.val.show_future_jobs = false
-	}
-
 	// Sync toggle state back to local storage when filters change
 	$effect(() => {
 		if (!filters.val.job_trigger_kind || filters.val.job_trigger_kind === '!schedule') {