fix: an emptied selection is no shift anchor, and a deploy leaves no draft for the prompt to compare

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

frontend/src/lib/components/home/homeSelection.dom.test.ts

@@ -0,0 +1,59 @@
+import { describe, it, expect, beforeEach } from 'vitest'
+import { HomeSelection, type BulkItem } from './homeSelection.svelte'
+
+// A shift-click range resolves its ends through the rendered rows, so these need a
+// document: the keys come back from `[data-row-selection-key]` in visual order.
+function row(key: string): BulkItem {
+	return {
+		key,
+		kind: 'script',
+		path: key.slice('script/'.length),
+		displayPath: key.slice('script/'.length),
+		summary: '',
+		canWrite: true,
+		owner: true,
+		archived: false,
+		draftOnly: false,
+		isDraft: false,
+		rawApp: false
+	}
+}
+
+const a = row('script/f/a/one')
+const b = row('script/f/a/two')
+const c = row('script/f/a/three')
+
+function rendered(...items: BulkItem[]): HomeSelection {
+	document.body.innerHTML = items
+		.map((i) => `<div data-row-selection-key="${i.key}"></div>`)
+		.join('')
+	const s = new HomeSelection()
+	s.available = true
+	for (const i of items) s.register(i)
+	return s
+}
+
+describe('HomeSelection shift-range', () => {
+	beforeEach(() => {
+		document.body.innerHTML = ''
+	})
+
+	it('selects the span between the anchor and the clicked row', () => {
+		const s = rendered(a, b, c)
+		s.toggle(a)
+
+		s.toggle(c, true)
+
+		expect(s.items.map((i) => i.key)).toEqual([a.key, b.key, c.key])
+	})
+
+	it('does not reach back into a selection the user already emptied', () => {
+		const s = rendered(a, b, c)
+		s.toggle(a)
+		s.toggle(a)
+
+		s.toggle(c, true)
+
+		expect(s.items.map((i) => i.key)).toEqual([c.key])
+	})
+})

frontend/src/lib/components/home/homeSelection.svelte.ts

@@ -150,7 +150,10 @@ export class HomeSelection {
 		}
 		if (this.selected.has(item.key)) this.selected.delete(item.key)
 		else this.selected.set(item.key, item)
-		this.anchor = item.key
+		// Unticking the last row ends selection mode, so the row it was on is not an
+		// anchor any more: the next shift-click would otherwise reach back and select
+		// everything between it and the row the user just started from.
+		this.anchor = this.selected.size === 0 ? undefined : item.key
 	}
 
 	/** Visual order is read back from the DOM: the tree nests rows and pages them

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

@@ -501,6 +501,10 @@
 					// (unknown when another landed beside it), and the head is what is deployed,
 					// named by whoever deployed it rather than by the page load's author.
 					draftBaseVersion = version != null ? String(version) : undefined
+					// The deploy consumed the draft, so the prompt has nothing to compare: without
+					// this the timestamp fallback reads a load-time draft save against a deploy
+					// that just happened and opens on a row that no longer exists.
+					draftSavedAt = undefined
 					if (head != null) {
 						deployedHeadVersion = String(head)
 						deployedBy = headBy

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

@@ -663,6 +663,10 @@
 					// than keeping the one it just superseded.
 					parentVersion = version
 					draftBaseVersion = version != null ? String(version) : undefined
+					// The deploy consumed the draft, so the prompt has nothing to compare: without
+					// this the timestamp fallback reads a load-time draft save against a deploy
+					// that just happened and opens on a row that no longer exists.
+					draftSavedAt = undefined
 					if (head != null) {
 						deployedHeadVersion = String(head)
 						// Named by whoever deployed the head, not by the page load's author.