fix: a failed anchor read is not a raced deploy, and take latest closes only its own drawer

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

frontend/src/lib/components/DiffDrawer.svelte

@@ -198,9 +198,13 @@
 	async function takeLatest() {
 		if (!data || data.mode !== 'normal' || !data.onTakeLatest || takingLatest) return
 		takingLatest = true
+		// Persisting the base is awaited, and this drawer outlives the editor that filled
+		// it: close only the opening this action belongs to, or it takes down whichever
+		// diff was opened meanwhile.
+		const opening = openingToken
 		try {
 			await data.onTakeLatest(headShown)
-			diffViewer?.closeDrawer()
+			if (opening === openingToken) diffViewer?.closeDrawer()
 		} finally {
 			takingLatest = false
 		}

frontend/src/lib/components/apps/editor/AppEditorHeader.svelte

@@ -369,10 +369,12 @@
 		policy = await updatePolicy($app, policy)
 		// Read the head this deploy is about to append to, so the entry it writes can be
 		// told from one landing beside it (see versionThisDeployWrote).
-		const headBefore = await AppService.getAppLatestVersion({
-			workspace: $workspaceStore!,
-			path: $appPath
-		}).catch(() => undefined)
+		const anchor = (
+			await AppService.getAppLatestVersion({
+				workspace: $workspaceStore!,
+				path: $appPath
+			}).catch(() => undefined)
+		)?.version
 		await AppService.updateApp({
 			workspace: $workspaceStore!,
 			path: $appPath!,
@@ -405,11 +407,13 @@
 		})
 		// `version` is what is deployed now, which is the deploy guard's fallback head and
 		// must stay set; `claimed` is the version this deploy can prove it wrote.
-		const claimed = versionThisDeployWrote(appHistory, $userStore?.username, headBefore?.version)
+		const claimed = versionThisDeployWrote(appHistory, $userStore?.username, anchor)
 		version = appHistory[0]?.version
-		// Without a claim the head is someone else's as far as this editor knows, so it is
-		// no longer a base it may compare against: `compareVersions` confirms instead.
-		baseUnknown = claimed === undefined
+		// A deploy landed beside this one, so the head is someone else's as far as this
+		// editor knows and is no longer a base it may compare against: `compareVersions`
+		// confirms instead. A failed anchor read claims nothing either, but it is no
+		// evidence of that, so it does not arm this.
+		baseUnknown = claimed === undefined && anchor != null
 		// Re-pin the fork base to the version just written: the editor stays open, so a
 		// follow-up deploy (or a new edit) would otherwise compare against the now-
 		// superseded base and falsely warn. parent_version is in

frontend/src/lib/components/apps/editor/appDeploy.svelte.ts

@@ -7,6 +7,9 @@ export function computeSecretUrl(secretUrl: string) {
 }
 
 /**
+ * Shared by both app editors: classic and raw apps deploy into the same `app_version`
+ * table and read the same history, so the rule for claiming a version lives here once.
+ *
  * The version a just-finished deploy wrote: this caller's newest entry, and only while it
  * sits directly on `headBefore`, the head read just before the write. That is what the
  * write appended, so anything else in between belongs to a deploy this cannot tell from

frontend/src/lib/components/common/confirmationModal/DraftEditorModals.svelte

@@ -98,10 +98,10 @@
 	// staleness outright.
 	const useVersion = $derived(draftBaseVersion != null && deployedHeadVersion != null)
 	const isStale = $derived(
-		// Both paths need a draft to be out of date: the editors clear `draftSavedAt`
-		// when a deploy consumes theirs, and the version pair stays armed for the draft
-		// the next edit starts, which is what the prompt would otherwise offer to
-		// discard seconds after a successful deploy.
+		// Both paths need a draft to be out of date: the app editors stay open across a
+		// deploy and clear `draftSavedAt` when it consumes theirs, while the version pair
+		// stays armed for the draft the next edit starts, which is what the prompt would
+		// otherwise offer to discard seconds after a successful deploy.
 		!!onLoadLatestDeploy &&
 			!!draftSavedAt &&
 			(useVersion

frontend/src/lib/components/raw_apps/RawAppEditorHeader.svelte

@@ -521,10 +521,12 @@
 		}
 		// Read the head this deploy is about to append to, so the entry it writes can be
 		// told from one landing beside it (see versionThisDeployWrote).
-		const headBefore = await AppService.getAppLatestVersion({
-			workspace: opWorkspace!,
-			path: appPath!
-		}).catch(() => undefined)
+		const anchor = (
+			await AppService.getAppLatestVersion({
+				workspace: opWorkspace!,
+				path: appPath!
+			}).catch(() => undefined)
+		)?.version
 		await AppService.updateAppRaw({
 			workspace: opWorkspace!,
 			path: appPath!,
@@ -563,11 +565,13 @@
 		// draft's base; the head is what is deployed now. The route owns this `version`
 		// prop and re-pushes `parentVersion ?? head` as soon as `onDeploy` returns, so the
 		// guard compares the claimed base when there is one and the head otherwise.
-		const claimed = versionThisDeployWrote(appHistory, $userStore?.username, headBefore?.version)
+		const claimed = versionThisDeployWrote(appHistory, $userStore?.username, anchor)
 		version = appHistory[0]?.version
-		// Without a claim the head is someone else's as far as this editor knows, so it is
-		// no longer a base it may compare against: `compareVersions` confirms instead.
-		baseUnknown = claimed === undefined
+		// A deploy landed beside this one, so the head is someone else's as far as this
+		// editor knows and is no longer a base it may compare against: `compareVersions`
+		// confirms instead. A failed anchor read claims nothing either, but it is no
+		// evidence of that, so it does not arm this.
+		baseUnknown = claimed === undefined && anchor != null
 
 		closeSaveDrawer()
 		sendUserToast('App deployed successfully')