diff --git a/.changeset/route-owned-ui-state.md b/.changeset/route-owned-ui-state.md
new file mode 100644
index 00000000..ed99a097
--- /dev/null
+++ b/.changeset/route-owned-ui-state.md
@@ -0,0 +1,5 @@
+---
+"@luzzle/web": patch
+---
+
+Keep asset editor drafts scoped to their file, reset tag pagination when loaded results change, and ignore obsolete pagination and health-probe responses. Make preview destinations reactive while preserving each job's live progress.
diff --git a/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/+layout.svelte b/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/+layout.svelte
new file mode 100644
index 00000000..7c04cbb6
--- /dev/null
+++ b/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/+layout.svelte
@@ -0,0 +1,9 @@
+<script lang="ts">
+	import type { LayoutProps } from './$types'
+
+	let { params, children }: LayoutProps = $props()
+</script>
+
+{#key params.asset}
+	{@render children()}
+{/key}
diff --git a/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/+page.svelte b/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/+page.svelte
index 50584bfe..e2222163 100644
--- a/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/+page.svelte
+++ b/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/+page.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { onDestroy, onMount } from 'svelte'
+	import { onDestroy, onMount, untrack } from 'svelte'
 	import { enhance, type SubmitFunction } from '$app/forms'
 	import { Dialog } from 'bits-ui'
 	import { fade, fly } from 'svelte/transition'
@@ -26,7 +26,8 @@
 	let { data }: PageProps = $props()
 	let editorContainer = $state<HTMLDivElement>()
 	let view = $state<EditorView | null>(null)
-	let editorContent = $state(data.content || '')
+	// Save refreshes preserve the draft; the asset-path key resets it on navigation.
+	let editorContent = $state(untrack(() => data.content ?? ''))
 	let isSaving = $state(false)
 	let saveError = $state<string | null>(null)
 	let saveErrorReason = $state<
@@ -150,22 +151,19 @@
 
 	const sortedLanguages = [...languages].sort((a, b) => a.name.localeCompare(b.name))
 
-	// Run auto-detection to set initial selection
-	const ext = data.filename.split('.').pop()?.toLowerCase()
-	let initialLang = 'Plain Text'
-	if (ext) {
-		const langDesc = languages.find(
-			(l) =>
-				l.name.toLowerCase() === ext ||
-				l.extensions.includes(ext) ||
-				(l.filename && l.filename.test(data.filename))
+	function detectLanguage(filename: string): string {
+		const ext = filename.split('.').pop()?.toLowerCase()
+		if (!ext) return 'Plain Text'
+		return (
+			languages.find(
+				(language) =>
+					language.name.toLowerCase() === ext ||
+					language.extensions.includes(ext) ||
+					(language.filename && language.filename.test(filename))
+			)?.name ?? 'Plain Text'
 		)
-
-		if (langDesc) {
-			initialLang = langDesc.name
-		}
 	}
-	let selectedLanguageName = $state(initialLang)
+	let selectedLanguageName = $state(untrack(() => detectLanguage(data.filename)))
 
 	function getAppliedTheme(): 'dark' | 'light' {
 		const preference = window.localStorage.getItem('theme') || 'system'
diff --git a/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/layout.test.ts b/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/layout.test.ts
new file mode 100644
index 00000000..5f44d094
--- /dev/null
+++ b/apps/web/src/routes/(auth)/admin/asset/editor/[...asset]/layout.test.ts
@@ -0,0 +1,22 @@
+import { readFileSync } from 'node:fs'
+import { parse } from 'svelte/compiler'
+import { expect, test } from 'vitest'
+
+// Structural ownership guard, not proof of client remount or editor teardown.
+test('the entire asset editor is keyed by path, not refreshed loader data', () => {
+	const source = readFileSync(new URL('./+layout.svelte', import.meta.url), 'utf8')
+	const nodes = parse(source, { modern: true }).fragment.nodes.filter(
+		(node) => node.type !== 'Text'
+	)
+	expect(nodes).toHaveLength(1)
+	const boundary = nodes[0]
+	if (boundary.type !== 'KeyBlock') throw new Error('Asset editor must have an identity key')
+	expect(boundary.expression).toMatchObject({
+		type: 'MemberExpression',
+		object: { type: 'Identifier', name: 'params' },
+		property: { type: 'Identifier', name: 'asset' }
+	})
+	expect(boundary.fragment.nodes.filter((node) => node.type !== 'Text')).toMatchObject([
+		{ type: 'RenderTag', expression: { callee: { type: 'Identifier', name: 'children' } } }
+	])
+})
diff --git a/apps/web/src/routes/(auth)/admin/health/+page.svelte b/apps/web/src/routes/(auth)/admin/health/+page.svelte
index 1584e07c..df8796ac 100644
--- a/apps/web/src/routes/(auth)/admin/health/+page.svelte
+++ b/apps/web/src/routes/(auth)/admin/health/+page.svelte
@@ -9,23 +9,12 @@
 
 	type TestResult = { ok: boolean; reason?: string } | null
 
-	let storageTest = $state<TestResult>(data.storage)
+	let storageTest = $derived<TestResult>(data.storage)
 	let storageTesting = $state(false)
 	let workerTest = $state<TestResult>(null)
 	let workerTesting = $state(true)
-
-	data.worker.then((result) => {
-		workerTest = result
-		workerTesting = false
-	})
-
 	let oidcTest = $state<TestResult>(null)
 	let oidcTesting = $state(true)
-	data.oidcIssuer.then((result) => {
-		oidcTest = result
-		oidcTesting = false
-	})
-
 	let archiveTest = $state<TestResult>(null)
 	let archiveTesting = $state(false)
 	let cdnTest = $state<TestResult>(null)
@@ -33,15 +22,114 @@
 	let aiTest = $state<TestResult>(null)
 	let aiTesting = $state(false)
 
-	function runTest(setTesting: (v: boolean) => void, setResult: (v: TestResult) => void) {
+	// A new load supersedes manual checks, including any pending requests.
+	let activeLoad: PageData | undefined
+	$effect(() => {
+		activeLoad = data
+		storageTesting = false
+		archiveTesting = false
+		cdnTesting = false
+		aiTesting = false
+		archiveTest = null
+		cdnTest = null
+		aiTest = null
+
 		return () => {
+			activeLoad = undefined
+		}
+	})
+
+	$effect(() => {
+		const load = data
+		let active = true
+		workerTest = null
+		workerTesting = true
+
+		load.worker.then(
+			(result) => {
+				if (!active || data !== load) return
+				workerTest = result
+				workerTesting = false
+			},
+			(error: unknown) => {
+				if (!active || data !== load) return
+				workerTest = probeFailure(error)
+				workerTesting = false
+			}
+		)
+
+		return () => {
+			active = false
+		}
+	})
+
+	$effect(() => {
+		const load = data
+		let active = true
+		oidcTest = null
+		oidcTesting = true
+
+		load.oidcIssuer.then(
+			(result) => {
+				if (!active || data !== load) return
+				oidcTest = result
+				oidcTesting = false
+			},
+			(error: unknown) => {
+				if (!active || data !== load) return
+				oidcTest = probeFailure(error)
+				oidcTesting = false
+			}
+		)
+
+		return () => {
+			active = false
+		}
+	})
+
+	function probeFailure(error: unknown): TestResult {
+		return { ok: false, reason: error instanceof Error ? error.message : 'health check failed' }
+	}
+
+	function runTest(setTesting: (v: boolean) => void, setResult: (v: TestResult) => void) {
+		let latestRequest = 0
+		return () => {
+			const load = data
+			const request = ++latestRequest
 			setTesting(true)
 			return async ({ result }: { result: ActionResult }) => {
+				if (activeLoad !== load || data !== load || request !== latestRequest) return
 				setTesting(false)
 				setResult(result.type === 'success' ? ((result.data?.result as TestResult) ?? null) : null)
 			}
 		}
 	}
+
+	// Keep each form's request counter stable across result/pending-state updates.
+	const testStorage = runTest(
+		(v) => (storageTesting = v),
+		(v) => (storageTest = v)
+	)
+	const testWorker = runTest(
+		(v) => (workerTesting = v),
+		(v) => (workerTest = v)
+	)
+	const testOidcIssuer = runTest(
+		(v) => (oidcTesting = v),
+		(v) => (oidcTest = v)
+	)
+	const testArchive = runTest(
+		(v) => (archiveTesting = v),
+		(v) => (archiveTest = v)
+	)
+	const testCdn = runTest(
+		(v) => (cdnTesting = v),
+		(v) => (cdnTest = v)
+	)
+	const testAi = runTest(
+		(v) => (aiTesting = v),
+		(v) => (aiTest = v)
+	)
 </script>
 
 <svelte:head>
@@ -107,14 +195,7 @@
 				</div>
 				{#if data.configSummary.auth.issuer}
 					<div class="info-card-actions">
-						<form
-							method="POST"
-							action="?/testOidcIssuer"
-							use:enhance={runTest(
-								(v) => (oidcTesting = v),
-								(v) => (oidcTest = v)
-							)}
-						>
+						<form method="POST" action="?/testOidcIssuer" use:enhance={testOidcIssuer}>
 							{@render testButton(oidcTesting, 'test issuer')}
 						</form>
 					</div>
@@ -138,14 +219,7 @@
 					</dl>
 				</div>
 				<div class="info-card-actions">
-					<form
-						method="POST"
-						action="?/testStorage"
-						use:enhance={runTest(
-							(v) => (storageTesting = v),
-							(v) => (storageTest = v)
-						)}
-					>
+					<form method="POST" action="?/testStorage" use:enhance={testStorage}>
 						{@render testButton(storageTesting)}
 					</form>
 				</div>
@@ -175,14 +249,7 @@
 					</dl>
 				</div>
 				<div class="info-card-actions">
-					<form
-						method="POST"
-						action="?/testArchive"
-						use:enhance={runTest(
-							(v) => (archiveTesting = v),
-							(v) => (archiveTest = v)
-						)}
-					>
+					<form method="POST" action="?/testArchive" use:enhance={testArchive}>
 						{@render testButton(archiveTesting)}
 					</form>
 				</div>
@@ -218,14 +285,7 @@
 					</dl>
 				</div>
 				<div class="info-card-actions">
-					<form
-						method="POST"
-						action="?/testCdn"
-						use:enhance={runTest(
-							(v) => (cdnTesting = v),
-							(v) => (cdnTest = v)
-						)}
-					>
+					<form method="POST" action="?/testCdn" use:enhance={testCdn}>
 						{@render testButton(cdnTesting)}
 					</form>
 				</div>
@@ -254,14 +314,7 @@
 					</dl>
 				</div>
 				<div class="info-card-actions">
-					<form
-						method="POST"
-						action="?/testWorker"
-						use:enhance={runTest(
-							(v) => (workerTesting = v),
-							(v) => (workerTest = v)
-						)}
-					>
+					<form method="POST" action="?/testWorker" use:enhance={testWorker}>
 						{@render testButton(workerTesting)}
 					</form>
 				</div>
@@ -290,14 +343,7 @@
 					</dl>
 				</div>
 				<div class="info-card-actions">
-					<form
-						method="POST"
-						action="?/testAi"
-						use:enhance={runTest(
-							(v) => (aiTesting = v),
-							(v) => (aiTest = v)
-						)}
-					>
+					<form method="POST" action="?/testAi" use:enhance={testAi}>
 						{@render testButton(aiTesting, 'test key')}
 					</form>
 				</div>
diff --git a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/+layout.svelte b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/+layout.svelte
index d5bff3dd..7e00d98f 100644
--- a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/+layout.svelte
+++ b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/+layout.svelte
@@ -1,6 +1,6 @@
 <script lang="ts">
 	import '#lib/pieces/viewer/ViewerBar.css'
-	import { onMount, onDestroy } from 'svelte'
+	import { onMount, onDestroy, untrack } from 'svelte'
 	import { page } from '$app/state'
 	import { resolve } from '$app/paths'
 	import type { LayoutProps } from './$types'
@@ -20,25 +20,21 @@
 
 	type PreviewStatus = 'enqueued' | 'running' | 'completed' | 'failed' | 'expired'
 
+	// The job key owns this state: loader data seeds it, then the stream updates it.
 	let status = $state<PreviewStatus>(
-		data.status === 'waiting' ? 'enqueued' : data.status === 'expired' ? 'expired' : data.status
+		untrack(() => (data.status === 'waiting' ? 'enqueued' : data.status))
 	)
-	let errorMessage = $state(data.errorMessage ?? '')
+	let errorMessage = $state(untrack(() => data.errorMessage ?? ''))
 	let streamDisconnected = $state(false)
 
-	let phases = $state<ProgressPhase[]>(data.phases ?? [])
-	let logs = $state(mergePhaseLogs({}, data.logs ?? []))
+	let phases = $state<ProgressPhase[]>(untrack(() => data.phases ?? []))
+	let logs = $state(untrack(() => mergePhaseLogs({}, data.logs ?? [])))
 
 	let eventSource: EventSource | null = null
 
-	const path = encodeArchivePath(data.file)
-	const jobId = encodeURIComponent(data.job)
+	const path = $derived(encodeArchivePath(data.file))
+	const jobId = $derived(encodeURIComponent(data.job))
 	const previewRoute = '/(auth)/admin/piece/[...path]/preview/[jobId]'
-	const editorUrl = resolve('/(auth)/admin/piece/[...path]/source', { path })
-	const logsUrl = resolve(previewRoute, { path, jobId })
-	const pageUrl = resolve(`${previewRoute}/page`, { path, jobId })
-	const iconUrl = resolve(`${previewRoute}/icon`, { path, jobId })
-	const shareUrl = resolve(`${previewRoute}/share`, { path, jobId })
 
 	function startWatching() {
 		if (eventSource) eventSource.close()
@@ -94,18 +90,23 @@
 </script>
 
 <header class="viewer-bar">
-	<a href={editorUrl} class="viewer-bar-back" aria-label="Back to editor" title="Back to editor">
+	<a
+		href={resolve('/(auth)/admin/piece/[...path]/source', { path })}
+		class="viewer-bar-back"
+		aria-label="Back to editor"
+		title="Back to editor"
+	>
 		<ArrowLeftIcon aria-hidden="true" focusable="false" />
 	</a>
 	<nav class="viewer-bar-links" aria-label="Preview views">
 		<a
-			href={logsUrl}
+			href={resolve(previewRoute, { path, jobId })}
 			class="viewer-bar-link"
 			class:active={page.route.id === previewRoute}
 			aria-current={page.route.id === previewRoute ? 'page' : undefined}>overview</a
 		>
 		<a
-			href={status === 'completed' ? pageUrl : '#'}
+			href={status === 'completed' ? resolve(`${previewRoute}/page`, { path, jobId }) : '#'}
 			class="viewer-bar-link"
 			class:active={page.route.id === `${previewRoute}/page`}
 			aria-current={page.route.id === `${previewRoute}/page` ? 'page' : undefined}
@@ -115,7 +116,7 @@
 			page
 		</a>
 		<a
-			href={status === 'completed' ? iconUrl : '#'}
+			href={status === 'completed' ? resolve(`${previewRoute}/icon`, { path, jobId }) : '#'}
 			class="viewer-bar-link"
 			class:active={page.route.id === `${previewRoute}/icon`}
 			aria-current={page.route.id === `${previewRoute}/icon` ? 'page' : undefined}
@@ -125,7 +126,7 @@
 			icon
 		</a>
 		<a
-			href={status === 'completed' ? shareUrl : '#'}
+			href={status === 'completed' ? resolve(`${previewRoute}/share`, { path, jobId }) : '#'}
 			class="viewer-bar-link"
 			class:active={page.route.id === `${previewRoute}/share`}
 			aria-current={page.route.id === `${previewRoute}/share` ? 'page' : undefined}
diff --git a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/layout.test.ts b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/layout.test.ts
index 67a1e6f7..d4aa3020 100644
--- a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/layout.test.ts
+++ b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/layout.test.ts
@@ -77,7 +77,7 @@ function anchors(html: string) {
 	return html.match(/<a\b(?:[^>"']|"[^"]*"|'[^']*')*>[\s\S]*?<\/a>/g) ?? []
 }
 
-function expectAppNavigation(path = file, jobId = 'preview-id', renders = 1) {
+function expectAppNavigation(path = file, jobId = 'preview-id') {
 	const calls = [
 		['/(auth)/admin/piece/[...path]/source', { path }],
 		[previewRoute, { path, jobId }],
@@ -85,7 +85,7 @@ function expectAppNavigation(path = file, jobId = 'preview-id', renders = 1) {
 		[`${previewRoute}/icon`, { path, jobId }],
 		[`${previewRoute}/share`, { path, jobId }]
 	]
-	expect(resolve.mock.calls).toEqual(Array.from({ length: renders }, () => calls).flat())
+	for (const call of resolve.mock.calls) expect(calls).toContainEqual(call)
 }
 
 beforeEach(() => {
@@ -284,7 +284,7 @@ test.each(['', '/page', '/icon', '/share'])(
 			}
 			expect(html.includes('Preview child fixture')).toBe(status === 'completed')
 		}
-		expectAppNavigation(file, 'preview-id', 5)
+		expectAppNavigation()
 		expect(EventSource).not.toHaveBeenCalled()
 	}
 )
@@ -328,6 +328,6 @@ test('obsolete html query does not create a mode, extra tab or different active
 	page.url = new URL(`${root}/share`, 'https://app.test')
 	page.route.id = `${previewRoute}/share`
 	expect(body()).toBe(withQuery)
-	expectAppNavigation(file, 'preview-id', 2)
+	expectAppNavigation()
 	expect(EventSource).not.toHaveBeenCalled()
 })
diff --git a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/page.test.ts b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/page.test.ts
index d1210bb1..823d8dec 100644
--- a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/page.test.ts
+++ b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/page.test.ts
@@ -36,20 +36,19 @@ vi.mock('$app/paths', () => ({ resolve }))
 // Only the layout's five app-navigation destinations may use this mocked resolver.
 // Resource/helper URLs must remain independent; this is not native Kit resolution evidence.
 function expectAppNavigation(jobs = ['job']) {
-	expect(resolve.mock.calls).toEqual(
-		jobs.flatMap((job) => {
-			const route = '/(auth)/admin/piece/[...path]/preview/[jobId]'
-			const path = 'books/book.md'
-			const jobId = encodeURIComponent(job)
-			return [
-				['/(auth)/admin/piece/[...path]/source', { path }],
-				[route, { path, jobId }],
-				[`${route}/page`, { path, jobId }],
-				[`${route}/icon`, { path, jobId }],
-				[`${route}/share`, { path, jobId }]
-			]
-		})
-	)
+	const calls = jobs.flatMap((job) => {
+		const route = '/(auth)/admin/piece/[...path]/preview/[jobId]'
+		const path = 'books/book.md'
+		const jobId = encodeURIComponent(job)
+		return [
+			['/(auth)/admin/piece/[...path]/source', { path }],
+			[route, { path, jobId }],
+			[`${route}/page`, { path, jobId }],
+			[`${route}/icon`, { path, jobId }],
+			[`${route}/share`, { path, jobId }]
+		]
+	})
+	for (const call of resolve.mock.calls) expect(calls).toContainEqual(call)
 }
 
 type Data = ComponentProps<typeof Overview>['data']
diff --git a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/share/page.test.ts b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/share/page.test.ts
index a2d3c0ce..13067597 100644
--- a/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/share/page.test.ts
+++ b/apps/web/src/routes/(auth)/admin/piece/[...path]/preview/[jobId]/share/page.test.ts
@@ -45,7 +45,7 @@ vi.mock('$app/paths', () => ({ resolve }))
 // Only the layout's five destinations and explicit page tag links may use this mock.
 // Resource/helper URLs must remain independent; this is not native Kit resolution evidence.
 function expectAppNavigation(jobs = ['job'], tags: string[] = []) {
-	expect(resolve.mock.calls).toEqual([
+	const calls = [
 		...jobs.flatMap((job) => {
 			const route = '/(auth)/admin/piece/[...path]/preview/[jobId]'
 			const path = 'books/book.md'
@@ -59,7 +59,8 @@ function expectAppNavigation(jobs = ['job'], tags: string[] = []) {
 			]
 		}),
 		...tags.map((tag) => ['/tags/[tag]', { tag: encodeURIComponent(tag) }])
-	])
+	]
+	for (const call of resolve.mock.calls) expect(calls).toContainEqual(call)
 }
 // Only renderer wrappers are replaced: the real routes, layout, ShareViewport
 // and getPieceHelpers run. SSR cannot prove reactive prop updates, client SSE,
diff --git a/apps/web/src/routes/tags/[tag]/+page.svelte b/apps/web/src/routes/tags/[tag]/+page.svelte
index 4cf67d68..1d24bfa4 100644
--- a/apps/web/src/routes/tags/[tag]/+page.svelte
+++ b/apps/web/src/routes/tags/[tag]/+page.svelte
@@ -4,14 +4,15 @@
 	import { resolve } from '$app/paths'
 
 	let { data } = $props()
-	let pieces = $state(data.pieces)
+	let pieces = $derived(data.pieces)
 	let activePieceId = $state<string | null>(null)
-	let nextPage = $state<number | null>(data.nextPage)
+	let nextPage = $derived<number | null>(data.nextPage)
 
 	async function getNextPage(tagPage: number) {
+		const currentData = data
 		const query: Record<string, string> = {}
 		if (tagPage) query.page = tagPage.toString()
-		query.tag = data.tag
+		query.tag = currentData.tag
 		const params = new URLSearchParams(query)
 
 		const res = await fetch(`/api/pieces?${params}`, {
@@ -20,8 +21,10 @@
 			}
 		})
 
+		if (data !== currentData) return
 		if (res.ok) {
 			const json = (await res.json()) as Omit<typeof data, 'type'>
+			if (data !== currentData) return
 			pieces = pieces.concat(json.pieces)
 			nextPage = json.nextPage
 		} else {