fix: a deploy always names the head it left behind, and pins a base only when it can claim one

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

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

@@ -398,12 +398,19 @@
 			workspace: $workspaceStore!,
 			path: npath
 		})
-		version = versionThisDeployWrote(appHistory, $userStore?.username, headBefore?.version)
+		// `version` is what is deployed now, which is the deploy guard's fallback head and
+		// must stay set; the pin below is the version this deploy can prove it wrote.
+		version = appHistory[0]?.version
 		// Re-pin the fork base to the version just written: the editor stays open, so a
 		// follow-up deploy (or a new edit) would otherwise compare against the now-
 		// superseded base and falsely warn. parent_version is in
 		// DRAFT_COMPARE_IGNORED_FIELDS, so this write can't spawn a spurious draft.
-		if ($app) $app.parent_version = version
+		if ($app)
+			$app.parent_version = versionThisDeployWrote(
+				appHistory,
+				$userStore?.username,
+				headBefore?.version
+			)
 
 		closeSaveDrawer()
 		sendUserToast('App deployed successfully')

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

@@ -20,8 +20,8 @@ describe('versionThisDeployWrote', () => {
 	})
 
 	it('claims nothing it cannot tell apart from another deploy', () => {
-		// The same account deploying from elsewhere is indistinguishable by author, so
-		// the entry has to sit on the head this deploy read, and this one does not.
+		// Two entries of the caller's sit above the head it read, so neither can be shown
+		// to be this deploy's: taking either would pin a version it may not have written.
 		expect(versionThisDeployWrote([alice(9), alice(7), bob(6)], 'alice', 6)).toBe(undefined)
 		expect(versionThisDeployWrote([bob(8), bob(6)], 'alice', 6)).toBe(undefined)
 		expect(versionThisDeployWrote([], 'alice', 6)).toBe(undefined)

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

@@ -552,9 +552,11 @@
 			workspace: opWorkspace!,
 			path: npath
 		})
-		// The version this deploy wrote, not the head: they differ when someone else's
-		// deploy landed in between, and this becomes the next draft's base below.
-		version = versionThisDeployWrote(appHistory, $userStore?.username, headBefore?.version)
+		// Two different things: `version` is what is deployed now, which is what the deploy
+		// guard compares against and must stay set, and `claimed` is the version this deploy
+		// can prove it wrote, which is the next draft's base.
+		const claimed = versionThisDeployWrote(appHistory, $userStore?.username, headBefore?.version)
+		version = appHistory[0]?.version
 
 		closeSaveDrawer()
 		sendUserToast('App deployed successfully')
@@ -569,7 +571,7 @@
 		if (appPath !== npath) {
 			onSavedNewAppPath?.(npath)
 		}
-		onDeploy?.({ path: npath, version, head: appHistory[0]?.version })
+		onDeploy?.({ path: npath, version: claimed, head: version })
 	}
 
 	async function setPublishState(message?: string) {

frontend/src/routes/(root)/(logged)/apps_raw/edit/[...path]/+page.svelte

@@ -658,11 +658,11 @@
 				onDeploy={({ version, head }) => {
 					// The version this deploy wrote is the base the next autosave carries; the
 					// head is what is deployed now. They differ when another deploy landed
-					// beside this one, and the next draft is then behind from the start.
-					if (version != null) {
-						parentVersion = version
-						draftBaseVersion = String(version)
-					}
+					// beside this one, and the next draft is then behind from the start. A
+					// deploy that could not claim a version leaves the base unknown rather
+					// than keeping the one it just superseded.
+					parentVersion = version
+					draftBaseVersion = version != null ? String(version) : undefined
 					if (head != null) {
 						deployedHeadVersion = String(head)
 					}