From 9e4ffe5cee674446fb4e927577c95121b64a00a0 Mon Sep 17 00:00:00 2001
From: xarmian <xarmian@gmail.com>
Date: Fri, 25 Sep 2026 23:30:49 -0400
Subject: [PATCH] fix(web): a field value whose shape does not match its
 declared type shows its raw text with a note and is replaced explicitly,
 never coerced (BUG-3052 unit 2) (#1556)

---
 web/e2e/bug-3052-field-shape-mismatch.spec.ts |  97 ++++++++++++
 .../TableView.listValue.svelte.test.ts        |  27 ++++
 .../components/collections/TableView.svelte   |  23 ++-
 .../FieldEditor.shapeMismatch.svelte.test.ts  | 144 ++++++++++++++++++
 .../lib/components/fields/FieldEditor.svelte  |  86 ++++++++++-
 .../components/items/CopyItemDialog.svelte    |   6 +-
 web/src/lib/fields/fieldShape.test.ts         |  63 +++++++-
 web/src/lib/fields/fieldShape.ts              |  74 ++++++++-
 web/src/lib/items/copyNeedsValue.ts           |   6 +-
 .../[workspace]/[collection]/+page.svelte     |   9 +-
 10 files changed, 518 insertions(+), 17 deletions(-)
 create mode 100644 web/e2e/bug-3052-field-shape-mismatch.spec.ts
 create mode 100644 web/src/lib/components/fields/FieldEditor.shapeMismatch.svelte.test.ts

diff --git a/web/e2e/bug-3052-field-shape-mismatch.spec.ts b/web/e2e/bug-3052-field-shape-mismatch.spec.ts
new file mode 100644
index 000000000..61542dd02
--- /dev/null
+++ b/web/e2e/bug-3052-field-shape-mismatch.spec.ts
@@ -0,0 +1,97 @@
+import { test, expect } from './fixtures';
+import { browserLogin } from './lib/collab-helpers';
+import { authJson, createCollection, deleteCollection } from './lib/attachment-viewer';
+import type { APIRequestContext } from '@playwright/test';
+import type { SuiteFixture } from './fixtures';
+
+/**
+ * BUG-3052 unit 2: a stored value whose shape does not match its field's
+ * declared type is shown in the item page as its raw text with a note, and an
+ * edit replaces it explicitly.
+ *
+ * The component legs mount FieldEditor with the value they choose. This leg is
+ * about what the PAGE hands it, which the component legs cannot see: ItemDetail
+ * passes an unset field as `''`, and the first version of the shape check read
+ * that as "not a number" and marked every empty number field on every item.
+ * So the proving pair is one item that must carry the marker and one that must
+ * not.
+ */
+
+async function createItem(
+	fixture: SuiteFixture,
+	request: APIRequestContext,
+	collSlug: string,
+	title: string,
+	fields: Record<string, unknown>,
+): Promise<{ slug: string }> {
+	const resp = await request.post(
+		`/api/v1/workspaces/${fixture.workspaceSlug}/collections/${collSlug}/items`,
+		{ headers: authJson(fixture), data: { title, fields: JSON.stringify(fields), content: '' } },
+	);
+	if (!resp.ok()) throw new Error(`item create failed (${resp.status()}): ${await resp.text()}`);
+	return (await resp.json()) as { slug: string };
+}
+
+async function setSchema(fixture: SuiteFixture, request: APIRequestContext, slug: string, schema: unknown) {
+	const resp = await request.patch(`/api/v1/workspaces/${fixture.workspaceSlug}/collections/${slug}`, {
+		headers: authJson(fixture),
+		data: { schema: JSON.stringify(schema) },
+	});
+	if (!resp.ok()) throw new Error(`collection patch failed (${resp.status()}): ${await resp.text()}`);
+}
+
+async function storedEffort(fixture: SuiteFixture, request: APIRequestContext, slug: string): Promise<unknown> {
+	const resp = await request.get(`/api/v1/workspaces/${fixture.workspaceSlug}/items/${slug}`, {
+		headers: authJson(fixture),
+	});
+	const body = (await resp.json()) as { fields: string | Record<string, unknown> };
+	const fields = typeof body.fields === 'string' ? JSON.parse(body.fields) : body.fields;
+	return (fields as Record<string, unknown>).effort;
+}
+
+test.describe('a field value whose shape does not match its type (BUG-3052 unit 2)', () => {
+	test.setTimeout(90_000);
+	test.beforeEach(({}, testInfo) => {
+		test.skip(testInfo.project.name !== 'desktop-chromium', 'one project is enough for a data-shape concern');
+	});
+
+	test('is marked on the item that holds it, not on an item where the field is unset, and Replace writes a number', async ({
+		page,
+		fixture,
+		request,
+	}) => {
+		const stamp = Date.now();
+		const coll = await createCollection(fixture, request, `Efforts ${stamp}`);
+		try {
+			await setSchema(fixture, request, coll.slug, { fields: [{ key: 'effort', label: 'Effort', type: 'text' }] });
+			const texty = await createItem(fixture, request, coll.slug, `Texty ${stamp}`, { effort: '5' });
+			const unset = await createItem(fixture, request, coll.slug, `Unset ${stamp}`, {});
+			// The retype rewrites nothing: `effort` is still the STRING "5".
+			await setSchema(fixture, request, coll.slug, { fields: [{ key: 'effort', label: 'Effort', type: 'number' }] });
+
+			await browserLogin(page);
+			const base = `/${fixture.adminUsername}/${fixture.workspaceSlug}/${coll.slug}`;
+
+			// Unset first: an empty number field is NOT a mismatch.
+			await page.goto(`${base}/${unset.slug}`);
+			await expect(page.locator('.number-input').first()).toBeVisible();
+			await expect(page.locator('.field-mismatch')).toHaveCount(0);
+
+			await page.goto(`${base}/${texty.slug}`);
+			const marker = page.locator('.field-mismatch');
+			await expect(marker).toBeVisible();
+			await expect(marker).toContainText('"5"');
+			await expect(marker).toContainText("Doesn't match the field type (number)");
+
+			await marker.getByRole('button', { name: 'Replace' }).click();
+			const input = page.locator('.number-input').first();
+			await expect(input).toHaveValue('');
+			await input.fill('3');
+			await input.blur();
+			await expect.poll(() => storedEffort(fixture, request, texty.slug)).toBe(3);
+			await expect(page.locator('.field-mismatch')).toHaveCount(0);
+		} finally {
+			await deleteCollection(fixture, request, coll.slug);
+		}
+	});
+});
diff --git a/web/src/lib/components/collections/TableView.listValue.svelte.test.ts b/web/src/lib/components/collections/TableView.listValue.svelte.test.ts
index 3e82e84f3..e94f744ed 100644
--- a/web/src/lib/components/collections/TableView.listValue.svelte.test.ts
+++ b/web/src/lib/components/collections/TableView.listValue.svelte.test.ts
@@ -377,3 +377,30 @@ describe('a text cell holding a value String() cannot convert (BUG-3052)', () =>
 		expect(screen.container.textContent).toContain('plain');
 	});
 });
+
+// BUG-3052 unit 2: a cell whose value does not match its field's declared type
+// shows the raw stored text, marked, instead of text that reads as well-typed.
+describe('a cell whose value does not match its field type (BUG-3052 unit 2)', () => {
+	it('shows the raw text, marked, and leaves well-typed cells alone', () => {
+		const coll = collection([
+			{ key: 'effort', label: 'Effort', type: 'number' },
+			{ key: 'note', label: 'Note', type: 'text' },
+		]);
+		const screen = render(TableView, {
+			props: {
+				items: [item('car-1', { effort: '5', note: { a: 1 } }), item('car-2', { effort: 3, note: 'plain' })],
+				collection: coll,
+			} as never,
+		});
+		const marked = [...screen.container.querySelectorAll('.cell-mismatch')];
+		expect(marked.map((el) => el.getAttribute('title'))).toEqual([
+			"Doesn't match the field type (number)",
+			"Doesn't match the field type (text)",
+		]);
+		// `"5"` is visibly not the number 5, and an object is not `[object Object]`.
+		expect(marked[0].textContent).toContain('"5"');
+		expect(marked[1].textContent).toContain('{"a":1}');
+		expect(screen.container.textContent).not.toContain('[object Object]');
+		expect(screen.container.textContent).toContain('plain');
+	});
+});
diff --git a/web/src/lib/components/collections/TableView.svelte b/web/src/lib/components/collections/TableView.svelte
index dcedebd98..df3460cc4 100644
--- a/web/src/lib/components/collections/TableView.svelte
+++ b/web/src/lib/components/collections/TableView.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { safeText } from '$lib/fields/fieldShape';
+	import { rawText, readAs, safeText } from '$lib/fields/fieldShape';
 	import type { Item, Collection, FieldDef } from '$lib/types';
 	import { isRelationType, relationValuesOf } from '$lib/items/relationFieldTypes';
 	import { narrowRelationRow, relationChipFor, UNRESOLVED_TITLE } from '$lib/collections/relationGroups';
@@ -355,8 +355,17 @@
 							{/if}
 						{:else}
 							<!-- safeText (BUG-3052): Svelte's text conversion threw on a
-							     stored `{"toString":0}` and took the table down. -->
-							<span class="cell-value">{safeText(fields[field.key])}</span>
+							     stored `{"toString":0}` and took the table down. A value
+							     whose shape does not match its declared type (unit 2)
+							     shows its raw stored text, marked, as FieldEditor does:
+							     an object no longer reads `[object Object]`, and `"5"`
+							     under a number is visibly not the number 5. -->
+							{@const cellShape = readAs(fields[field.key], field.type)}
+							{#if cellShape.ok}
+								<span class="cell-value">{safeText(fields[field.key])}</span>
+							{:else}
+								<span class="cell-value cell-mismatch" title="Doesn't match the field type ({field.type})">{rawText(fields[field.key])}<span class="sr-only"> (doesn't match the field type {field.type})</span></span>
+							{/if}
 						{/if}
 					</div>
 				{/each}
@@ -546,6 +555,14 @@
 		font-size: 0.9em;
 	}
 
+	/* A value whose shape does not match its declared type (BUG-3052 unit 2):
+	   raw stored text, set apart so it does not read as a well-typed value. */
+	.cell-mismatch {
+		font-family: var(--font-mono);
+		text-decoration: underline dotted var(--text-muted);
+		cursor: help;
+	}
+
 	/* Relation cells (BUG-3016). Same vocabulary as the properties chip, sized
 	   for a table cell: a single row that ellipsises rather than wrapping, so a
 	   long title cannot change the row's height. */
diff --git a/web/src/lib/components/fields/FieldEditor.shapeMismatch.svelte.test.ts b/web/src/lib/components/fields/FieldEditor.shapeMismatch.svelte.test.ts
new file mode 100644
index 000000000..9a48055df
--- /dev/null
+++ b/web/src/lib/components/fields/FieldEditor.shapeMismatch.svelte.test.ts
@@ -0,0 +1,144 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { render, cleanup } from '@testing-library/svelte';
+import { tick } from 'svelte';
+
+// A real epoch behind a mock, so the fence the component captures is the one an
+// identity change actually moves.
+const auth = vi.hoisted(() => {
+	let epoch = 0;
+	return {
+		identityFence() {
+			const captured = epoch;
+			return () => epoch === captured;
+		},
+		changeIdentity() {
+			epoch++;
+		},
+	};
+});
+vi.mock('$lib/stores/auth.svelte', () => ({ authStore: auth }));
+
+vi.mock('$lib/api/client', () => ({ api: { search: vi.fn(), items: { create: vi.fn() } } }));
+vi.mock('$lib/stores/localIndex.svelte', () => ({
+	localIndex: {
+		bootstrapStateFor: vi.fn(() => 'ready'),
+		findByIdOrSlug: vi.fn(),
+		getByCollection: vi.fn(() => []),
+		cursorFor: vi.fn(),
+		upsert: vi.fn(),
+		scopeEpochFor: vi.fn(),
+		pendingResyncFor: vi.fn(),
+		resetGenerationFor: vi.fn(),
+	},
+}));
+vi.mock('$lib/stores/localSearch.svelte', () => ({
+	localSearch: { search: vi.fn(() => []), epoch: vi.fn(() => 0) },
+}));
+vi.mock('$lib/stores/collections.svelte', () => ({
+	collectionStore: { collections: [], collectionsAreFreshFor: vi.fn(() => true) },
+}));
+vi.mock('$lib/stores/workspace.svelte', () => ({
+	workspaceStore: { canEditCollection: vi.fn(() => true) },
+}));
+vi.mock('$lib/stores/toast.svelte', () => ({ toastStore: { show: vi.fn() } }));
+
+
+import FieldEditor from './FieldEditor.svelte';
+
+/**
+ * BUG-3052 unit 2: a stored value whose SHAPE does not match its declared type
+ * is shown as its raw text with a note, never handed to the type's editor.
+ * The ruling: an edit REPLACES it explicitly, never a silent coercion.
+ *
+ * The defects these legs pin, each of which a strict reading of the type
+ * produced: the checkbox read `!!"false"` as CHECKED and its toggle wrote a
+ * boolean over the string; the number step turned `"5"` into 6 without asking.
+ */
+
+const flag = { key: 'blocked', label: 'Blocked', type: 'checkbox' as const };
+const effort = { key: 'effort', label: 'Effort', type: 'number' as const };
+const labels = { key: 'labels', label: 'Labels', type: 'multi_select' as const, options: ['a', 'b'] };
+
+afterEach(() => cleanup());
+
+const mismatch = (c: HTMLElement) => c.querySelector('.field-mismatch');
+const button = (c: HTMLElement, name: string) =>
+	[...c.querySelectorAll('button')].find((b) => b.textContent?.trim() === name) as HTMLButtonElement | undefined;
+
+describe('a value whose shape does not match its field (BUG-3052 unit 2)', () => {
+	it('checkbox holding the string "false": shown as its raw text, no switch, nothing written', async () => {
+		const onchange = vi.fn();
+		const { container } = render(FieldEditor, { props: { field: flag, value: 'false', onchange, itemId: 'i1' } });
+		expect(mismatch(container)?.textContent).toContain('"false"');
+		expect(mismatch(container)?.textContent).toContain("Doesn't match the field type (checkbox)");
+		// The switch that read `!!"false"` as checked is not offered at all.
+		expect(container.querySelector('[role="switch"]')).toBeNull();
+		expect(onchange).not.toHaveBeenCalled();
+	});
+
+	it('number holding "5": Replace opens the editor EMPTY, and only a step the user takes writes', async () => {
+		const onchange = vi.fn();
+		const { container } = render(FieldEditor, { props: { field: effort, value: '5', onchange, itemId: 'i1' } });
+		expect(container.querySelector('.number-input')).toBeNull();
+		button(container, 'Replace')!.click();
+		await tick();
+		const input = container.querySelector('.number-input') as HTMLInputElement;
+		expect(input).not.toBeNull();
+		expect(input.value).toBe('');
+		expect(onchange).not.toHaveBeenCalled();
+		(container.querySelector('[aria-label="Increase"]') as HTMLButtonElement).click();
+		await tick();
+		// Stepped from nothing, not from the string: never 6.
+		expect(onchange.mock.calls).toEqual([[1]]);
+	});
+
+	it('Keep the stored value backs out of a replace without writing', async () => {
+		const onchange = vi.fn();
+		const { container } = render(FieldEditor, { props: { field: effort, value: '5', onchange, itemId: 'i1' } });
+		button(container, 'Replace')!.click();
+		await tick();
+		button(container, 'Keep the stored value')!.click();
+		await tick();
+		expect(mismatch(container)?.textContent).toContain('"5"');
+		expect(onchange).not.toHaveBeenCalled();
+	});
+
+	it('a replace does not carry over to another item holding the same value', async () => {
+		const { container, rerender } = render(FieldEditor, {
+			props: { field: effort, value: '5', onchange: vi.fn(), itemId: 'i1' },
+		});
+		button(container, 'Replace')!.click();
+		await tick();
+		expect(mismatch(container)).toBeNull();
+		await rerender({ field: effort, value: '5', onchange: vi.fn(), itemId: 'i2' });
+		expect(mismatch(container)?.textContent).toContain('"5"');
+	});
+
+	it('read-only: the same marker, and no Replace', () => {
+		const { container } = render(FieldEditor, {
+			props: { field: effort, value: { n: 5 }, onchange: vi.fn(), itemId: 'i1', readonly: true },
+		});
+		expect(mismatch(container)?.textContent).toContain('{"n":5}');
+		expect(button(container, 'Replace')).toBeUndefined();
+	});
+
+	it('control: well-typed values render their editors, with no marker', () => {
+		const a = render(FieldEditor, { props: { field: flag, value: false, onchange: vi.fn(), itemId: 'i1' } });
+		expect(mismatch(a.container)).toBeNull();
+		expect(a.container.querySelector('[role="switch"]')?.getAttribute('aria-checked')).toBe('false');
+		cleanup();
+		const b = render(FieldEditor, { props: { field: effort, value: 5, onchange: vi.fn(), itemId: 'i1' } });
+		expect(mismatch(b.container)).toBeNull();
+		expect((b.container.querySelector('.number-input') as HTMLInputElement).value).toBe('5');
+	});
+});
+
+describe('multi_select has no editor here yet (BUG-3052 unit 2)', () => {
+	it('shows its values read-only with a hint, and no text input that would write a string', () => {
+		const onchange = vi.fn();
+		const { container } = render(FieldEditor, { props: { field: labels, value: ['a', 'b'], onchange, itemId: 'i1' } });
+		expect(container.querySelector('input')).toBeNull();
+		expect(container.textContent).toContain('a, b');
+		expect(container.textContent).toContain("Can't be edited here yet");
+	});
+});
diff --git a/web/src/lib/components/fields/FieldEditor.svelte b/web/src/lib/components/fields/FieldEditor.svelte
index 41021fd0a..7e79e3f91 100644
--- a/web/src/lib/components/fields/FieldEditor.svelte
+++ b/web/src/lib/components/fields/FieldEditor.svelte
@@ -18,6 +18,7 @@ handlers — onchange is never called.
 	import { onDestroy, tick } from 'svelte';
 	import { formatItemRef, type FieldDef, type ItemIndexRow, type PaneTarget } from '$lib/types';
 	import { localIndex } from '$lib/stores/localIndex.svelte';
+	import { rawText, readAs } from '$lib/fields/fieldShape';
 	import { narrowRelationRow, UNRESOLVED_LABEL, UNRESOLVED_TITLE } from '$lib/collections/relationGroups';
 	import {
 		isMultiRelationType,
@@ -106,7 +107,28 @@ handlers — onchange is never called.
 		itemId?: string;
 	}
 
-	let { field, value, onchange, readonly = false, ariaLabel, wsSlug, username = '', onOpenTarget, itemId }: Props = $props();
+	let { field, value: storedValue, onchange, readonly = false, ariaLabel, wsSlug, username = '', onOpenTarget, itemId }: Props = $props();
+
+	// ── Shape mismatch (BUG-3052 unit 2) ───────────────────────────────────
+	//
+	// A declared type is not a promise about the stored value: a retype
+	// rewrites nothing. A value whose SHAPE does not match (`"5"` under a
+	// number, `"false"` under a checkbox) is shown as its raw stored text with a
+	// note, never fed to the type's editor: the checkbox read `!!"false"` as
+	// checked and its toggle wrote a boolean over the string, and the number
+	// step converted the string. The ruling: an edit REPLACES the value
+	// explicitly, never a silent coercion. Replace opens the ordinary editor on
+	// an EMPTY value; nothing is written until the user sets one.
+	//
+	// The replace state is KEYED on (item, field, stored value) rather than a
+	// flag an effect resets, so switching items or a remote write ends it and
+	// the next item cannot inherit it.
+	let shape = $derived(readAs(storedValue, field.type));
+	let mismatchKey = $derived(`${itemId ?? ''}\u0000${field.key}\u0000${rawText(storedValue)}`);
+	let replacingKey = $state<string | null>(null);
+	let replacing = $derived(!shape.ok && replacingKey === mismatchKey);
+	/** What every editor branch below reads: the stored value, or nothing while replacing it. */
+	let value = $derived(shape.ok ? storedValue : undefined);
 
 	// ── Relation resolution ───────────────────────────────────────────────
 	//
@@ -1308,7 +1330,16 @@ handlers — onchange is never called.
 	{/if}
 {/snippet}
 
-{#if readonly}
+{#if !shape.ok && !replacing}
+	<div class="field-mismatch">
+		<span class="mismatch-raw">{rawText(storedValue)}</span>
+		<span class="mismatch-note">Doesn't match the field type ({field.type})</span>
+		{#if !readonly}
+			<button type="button" class="mismatch-action" onclick={() => (replacingKey = mismatchKey)}>Replace</button>
+		{/if}
+	</div>
+
+{:else if readonly}
 	<!--
 		Display-only mode (PLAN-1100 / TASK-1105). No inputs, no dropdowns,
 		no mutation handlers — value rendered with the same visual language
@@ -1681,8 +1712,18 @@ handlers — onchange is never called.
 		<span>{value === undefined || value === null ? '—' : JSON.stringify(value)}</span>
 	</div>
 
+{:else if field.type === 'multi_select'}
+	<!-- No multi_select editor exists here yet (BUG-3052 unit 2). The text
+	     input this used to fall to wrote a STRING, which the server refuses
+	     for a multi_select, so the values are shown read-only and the hint
+	     says so rather than leaving a dead field. -->
+	<div class="readonly-display" title="Multi-select values can't be edited here yet.">
+		<span>{Array.isArray(value) && value.length ? value.join(', ') : '—'}</span>
+		<span class="mismatch-note">Can't be edited here yet</span>
+	</div>
+
 {:else}
-	<!-- Text / Multi-select fallback -->
+	<!-- Text fallback -->
 	<input
 		class="field-input"
 		type="text"
@@ -1692,8 +1733,47 @@ handlers — onchange is never called.
 		onblur={flushPendingSave}
 	/>
 {/if}
+{#if replacing}
+	<button type="button" class="mismatch-action" onclick={() => (replacingKey = null)}>Keep the stored value</button>
+{/if}
 
 <style>
+	/* ── Shape mismatch (BUG-3052 unit 2) ─────────────────────────────── */
+
+	.field-mismatch {
+		display: flex;
+		flex-wrap: wrap;
+		align-items: center;
+		gap: var(--space-1) var(--space-2);
+		padding: var(--space-1) var(--space-2);
+		min-height: 30px;
+		font-size: 0.88em;
+	}
+
+	.mismatch-raw {
+		font-family: var(--font-mono);
+		color: var(--text-primary);
+		overflow-wrap: anywhere;
+	}
+
+	.mismatch-note {
+		font-size: 0.85em;
+		color: var(--text-muted);
+	}
+
+	.mismatch-action {
+		font-size: 0.85em;
+		color: var(--accent-blue);
+		background: none;
+		border: none;
+		padding: 0;
+		cursor: pointer;
+	}
+
+	.mismatch-action:hover {
+		text-decoration: underline;
+	}
+
 	/* ── Readonly display ─────────────────────────────────────────────── */
 
 	.readonly-display {
diff --git a/web/src/lib/components/items/CopyItemDialog.svelte b/web/src/lib/components/items/CopyItemDialog.svelte
index 987e53e02..1496b3845 100644
--- a/web/src/lib/components/items/CopyItemDialog.svelte
+++ b/web/src/lib/components/items/CopyItemDialog.svelte
@@ -130,9 +130,9 @@ user hunting for an item that provably does not exist.
 	 * Everything else is NOT rendered as a text box. `json` is deliberately
 	 * read-only in FieldEditor (a plain text input would store the string
 	 * "[]" where an array belongs), `relation` has no picker here, and
-	 * `multi_select` falls through FieldEditor's TEXT fallback — which yields a
-	 * string where the server's validation requires `[]any`. That last one is
-	 * the dangerous case: enterable and silently invalid. So a required field of
+	 * `multi_select` has no editor in FieldEditor (it fell through to the TEXT
+	 * fallback, a string where the server's validation requires `[]any`, until
+	 * BUG-3052 unit 2 made it read-only). So a required field of
 	 * any uncollectable type renders an explicit blocked state naming the field
 	 * and its type, rather than a dead Confirm or a lying input.
 	 *
diff --git a/web/src/lib/fields/fieldShape.test.ts b/web/src/lib/fields/fieldShape.test.ts
index 49cd558df..4ffeef5a7 100644
--- a/web/src/lib/fields/fieldShape.test.ts
+++ b/web/src/lib/fields/fieldShape.test.ts
@@ -1,6 +1,6 @@
 // BUG-3052 unit 1: the read-side text conversion never throws.
 import { describe, expect, it } from 'vitest';
-import { fieldMatches, safeString, safeText } from './fieldShape';
+import { fieldMatches, rawText, readAs, safeString, safeText } from './fieldShape';
 import { laneValue } from '$lib/collections/boardColumns';
 
 // A value JSON.parse happily produces, on which String() / `${}` / new Date() throw.
@@ -86,3 +86,64 @@ describe('fieldMatches', () => {
 		expect(fieldMatches('true', true)).toBe(true);
 	});
 });
+
+// BUG-3052 unit 2: the shape half of the server's validateFieldType, asked of a read.
+describe('readAs', () => {
+	const ok = (raw: unknown, t: string) => readAs(raw, t).ok;
+
+	it('accepts each type\'s own shape, and an absent value for any type', () => {
+		expect(ok('x', 'text')).toBe(true);
+		expect(ok('https://x', 'url')).toBe(true);
+		expect(ok('open', 'select')).toBe(true);
+		expect(ok('2026-09-26', 'date')).toBe(true);
+		expect(ok('2026-09-26T10:00:00Z', 'date')).toBe(true);
+		expect(ok('2026-09-26T23:59:59,5+05:30', 'date')).toBe(true);
+		expect(ok('', 'date')).toBe(true);
+		expect(ok(5, 'number')).toBe(true);
+		expect(ok(0, 'number')).toBe(true);
+		expect(ok(false, 'checkbox')).toBe(true);
+		expect(ok(['a'], 'multi_select')).toBe(true);
+		expect(ok([], 'multi_select')).toBe(true);
+		for (const t of ['text', 'number', 'checkbox', 'date', 'multi_select']) {
+			expect(ok(null, t), t).toBe(true);
+			expect(ok(undefined, t), t).toBe(true);
+			// ItemDetail passes an unset field as `''` (`fields[key] ?? ''`).
+			expect(ok('', t), t).toBe(true);
+		}
+	});
+
+	it('refuses what the server would refuse to write', () => {
+		expect(ok(5, 'text')).toBe(false);
+		expect(ok(['a'], 'select')).toBe(false);
+		expect(ok('5', 'number')).toBe(false);
+		expect(ok(Infinity, 'number')).toBe(false);
+		expect(ok('false', 'checkbox')).toBe(false);
+		expect(ok(0, 'checkbox')).toBe(false);
+
+		expect(ok(20260926, 'date')).toBe(false);
+		expect(ok('a', 'multi_select')).toBe(false);
+		expect(ok(['a', 1], 'multi_select')).toBe(false);
+		expect(ok(HOSTILE, 'text')).toBe(false);
+	});
+
+	it('judges a date by its JSON type only, not by whether it parses', () => {
+		// The value half (a date that parses, a select value that is an option)
+		// is the editor's to show; see readAs's comment for why.
+		expect(ok('next week', 'date')).toBe(true);
+		expect(ok('2026-99-99', 'date')).toBe(true);
+		expect(ok(20260926, 'date')).toBe(false);
+	});
+
+	it('does not judge json, relations or an unknown type', () => {
+		for (const t of ['json', 'relation', 'multi_relation', 'mystery']) expect(ok({ a: 1 }, t), t).toBe(true);
+	});
+});
+
+describe('rawText', () => {
+	it('is the stored JSON text, so a string shows quoted and an object shows its members', () => {
+		expect(rawText('5')).toBe('"5"');
+		expect(rawText({ a: 1 })).toBe('{"a":1}');
+		expect(rawText(HOSTILE)).toBe('{"toString":0}');
+		expect(rawText(undefined)).toBe('');
+	});
+});
diff --git a/web/src/lib/fields/fieldShape.ts b/web/src/lib/fields/fieldShape.ts
index b181ce899..7b89db335 100644
--- a/web/src/lib/fields/fieldShape.ts
+++ b/web/src/lib/fields/fieldShape.ts
@@ -25,8 +25,11 @@
 //   - playbooks page trigger sort
 //   - ItemDetail: children signature, computed-field text, imported-at title
 //   - ChildChart start/end dates
-// Unit 2 — renders garbage / writes back a changed type (FieldEditor,
-//   TableView cells): `readAs` + a mismatch marker; waits on a UX ruling.
+// Unit 2 — renders garbage / writes back a changed type, routed through
+//   `readAs` + `rawText`: FieldEditor (read-only and editable; a mismatch is
+//   shown raw with a note and replaced explicitly, never coerced), the
+//   TableView plain cell, and the bulk-move undo (offered only for a string
+//   status). multi_select has no FieldEditor editor and renders read-only.
 // Unit 3 — web misfilters, routed through `fieldMatches`: the collection
 //   page field filter, ChildItems + NestedChildren done checks, the command
 //   palette status chip, the playbooks trigger/scope filter, shareView
@@ -96,3 +99,70 @@ export function fieldMatches(raw: unknown, wanted: unknown, declaredType?: strin
 	}
 	return safeText(raw) === want;
 }
+
+/** The answer `readAs` gives: the value as its declared type, or the raw value. */
+export type ReadAs = { ok: true; value: unknown } | { ok: false; raw: unknown };
+
+/**
+ * Does a stored value have the SHAPE its declared type promises? (BUG-3052
+ * unit 2.) The question the server's `validateFieldType`
+ * (internal/items/validate.go) asks of a write, asked here of a read, so a value
+ * this marks as mismatched is one a write of the same bytes would refuse:
+ * text / url / select / date need a string, number a finite number, checkbox a
+ * boolean, multi_select an array of strings.
+ *
+ * Only the JSON-TYPE half. Two value questions the server also asks are NOT
+ * asked here: whether a select's string is one of its OPTIONS, and whether a
+ * date's string PARSES as a date. The type is what an editor misreads into a
+ * coercing write (`!!"false"`, a step from `"5"`); a well-typed string with a
+ * bad value is shown by its own editor and changed only when the user picks a
+ * new one. Mirroring the date half means mirroring Go's `time.Parse`, which
+ * accepts a one-digit hour and a `+24:00` offset and refuses `+25:00`, so a
+ * copy of it here would drift from it (BUG-3052 unit 2, review round 2). `json`, the
+ * relation types and any type this module does not know are not judged.
+ *
+ * NO VALUE is `null`, `undefined` and `''`, for every type, the same set
+ * `laneValue` treats as absent. `''` has to be in it: ItemDetail hands its
+ * editors `fields[key] ?? ''`, so an unset number or checkbox ARRIVES as `''`,
+ * and judging that as "not a number" marked every empty field in the pane.
+ */
+export function readAs(raw: unknown, declaredType: string): ReadAs {
+	if (raw == null || raw === '') return { ok: true, value: raw };
+	let ok: boolean;
+	switch (declaredType) {
+		case 'text':
+		case 'url':
+		case 'select':
+			ok = typeof raw === 'string';
+			break;
+		case 'date':
+			ok = typeof raw === 'string';
+			break;
+		case 'number':
+			ok = typeof raw === 'number' && Number.isFinite(raw);
+			break;
+		case 'checkbox':
+			ok = typeof raw === 'boolean';
+			break;
+		case 'multi_select':
+			ok = Array.isArray(raw) && raw.every((el) => typeof el === 'string');
+			break;
+		default:
+			ok = true;
+	}
+	return ok ? { ok: true, value: raw } : { ok: false, raw };
+}
+
+/**
+ * A stored value as its JSON text, for showing a value that does not match its
+ * field: a string shows QUOTED (`"5"` is visibly not the number 5), an object
+ * shows its members instead of `[object Object]`. TOTAL.
+ */
+export function rawText(raw: unknown): string {
+	if (raw === undefined) return '';
+	try {
+		return JSON.stringify(raw) ?? safeText(raw);
+	} catch {
+		return safeText(raw);
+	}
+}
diff --git a/web/src/lib/items/copyNeedsValue.ts b/web/src/lib/items/copyNeedsValue.ts
index 0fba7843b..0d4215aa3 100644
--- a/web/src/lib/items/copyNeedsValue.ts
+++ b/web/src/lib/items/copyNeedsValue.ts
@@ -7,9 +7,9 @@ import { isRelationType } from '$lib/items/relationFieldTypes';
  *
  * Everything else is NOT rendered as a text box. `json` is deliberately
  * read-only in FieldEditor (a plain text input would store the string "[]"
- * where an array belongs), and `multi_select` falls through FieldEditor's TEXT
- * fallback, which yields a string where the server requires `[]any`. That last
- * one is the dangerous case: enterable and silently invalid.
+ * where an array belongs), and `multi_select` has no editor in FieldEditor: it
+ * used to fall through to the TEXT fallback, which yielded a string where the
+ * server requires `[]any`, and since BUG-3052 unit 2 it renders read-only.
  */
 export const COLLECTABLE_TYPES = new Set([
 	'text',
diff --git a/web/src/routes/[username]/[workspace]/[collection]/+page.svelte b/web/src/routes/[username]/[workspace]/[collection]/+page.svelte
index 66dafc899..3fb332f29 100644
--- a/web/src/routes/[username]/[workspace]/[collection]/+page.svelte
+++ b/web/src/routes/[username]/[workspace]/[collection]/+page.svelte
@@ -3357,8 +3357,13 @@
 	}
 	function handleBulkMove(items: Item[], status: string) {
 		const ws = wsSlug;
-		// All lane items shared the lane's status; undo moves them back.
-		const sourceStatus = items.length ? String(parseFields(items[0]).status ?? '') : '';
+		// All lane items shared the lane's status; undo moves them back. Only a
+		// STRING status is written back (BUG-3052 unit 2): the lane key is the
+		// value's text, so moving a `5` back would store `"5"`, a silent change
+		// of type, and a `{"toString":0}` made `String` throw. No undo is offered
+		// for those rather than a coercing one.
+		const rawSource = items.length ? parseFields(items[0]).status : undefined;
+		const sourceStatus = typeof rawSource === 'string' ? rawSource : '';
 		return runBulkOn(ws, { op: 'move', ids: idsOf(items), status }, 'Moved', {
 			undo: sourceStatus
 				? (okIds) => runBulkOn(ws, { op: 'move', ids: okIds, status: sourceStatus }, 'Moved back')