diff --git a/CHANGELOG.md b/CHANGELOG.md
index e434fa01..7e43f3bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -61,6 +61,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   mode, delegating provider/model/topology policy to the shared service without
   weakening ScopeWeave's authenticated, fail-closed transport or response
   boundary controls.
+- Kept invalid editor save actions keyboard-discoverable with
+  `aria-disabled="true"` and an explicit `aria-describedby` relationship while
+  preserving synchronous submit-time validation as the only persistence gate;
+  immediately corrected click and Enter submissions now use the latest draft.
 - Accepted XML whitespace before exact Microsoft Project element delimiters
   while preserving the linear, regex-free import scanner and rejecting
   attributes, longer names, non-XML whitespace, nested unmatched blocks, and
diff --git a/app.js b/app.js
index a04aae71..bacbb51f 100644
--- a/app.js
+++ b/app.js
@@ -87,7 +87,7 @@ const CSV_HEADERS = [
   '스프린트',
   '스토리포인트'
 ];
-const CSV_FORMULA_PREFIX_PATTERN = /^\s*[=+\-@|]/;
+const CSV_FORMULA_PREFIX_PATTERN = /^\s*[=+\-@|＝＋－＠｜]/;
 const UNSAFE_JSON_KEYS = new Set(['__proto__', 'constructor', 'prototype']);
 
 const CSV_FIELD_LABELS = Object.freeze(Object.assign(Object.create(null), {
@@ -790,6 +790,9 @@ function renderEditorRow(anchorId) {
   panel.className = 'editor-panel';
   const form = document.createElement('form');
   form.dataset.editorForm = 'true';
+  // ScopeWeave validation is the sole persistence gate; native constraint
+  // validation would intercept submission and move focus before saveEditor().
+  form.noValidate = true;
   const editorGrid = document.createElement('div');
   editorGrid.className = 'editor-grid';
 
@@ -1068,7 +1071,13 @@ function renderEditorValidation() {
 
   const saveButton = form.querySelector('button[type="submit"]');
   if (saveButton) {
-    saveButton.disabled = errors.length > 0;
+    if (errors.length > 0) {
+      saveButton.setAttribute('aria-disabled', 'true');
+      saveButton.setAttribute('aria-describedby', 'editor-errors');
+    } else {
+      saveButton.removeAttribute('aria-disabled');
+      saveButton.removeAttribute('aria-describedby');
+    }
     saveButton.title = errors.length > 0 ? '입력값을 올바르게 수정해야 저장할 수 있습니다.' : '저장 (Enter)';
   }
 
diff --git a/docs/doctoring/editor-save-validation-accessibility.md b/docs/doctoring/editor-save-validation-accessibility.md
new file mode 100644
index 00000000..e65fbb8f
--- /dev/null
+++ b/docs/doctoring/editor-save-validation-accessibility.md
@@ -0,0 +1,75 @@
+# Focusable editor validation and synchronous save authority
+
+## Decision
+
+The editor save button remains a native button in the sequential keyboard order.
+When the current draft is invalid, ScopeWeave exposes
+`aria-disabled="true"`, connects the button to `#editor-errors` with
+`aria-describedby`, and keeps the control physically focusable. Activation is
+still accepted as an input event, but `saveEditor()` synchronously validates the
+latest draft and refuses persistence while errors remain.
+
+The debounced validation pass is presentation only. It updates field error
+states, the error summary, and save-button semantics; it is not an authorization
+or persistence boundary. This avoids two inverse races:
+
+- a user corrects the final error and immediately clicks or presses Enter before
+  the debounce updates a stale disabled state; and
+- a user introduces an error and immediately submits before the presentation
+  layer catches up.
+
+Both paths are decided by the same latest-draft validation inside
+`saveEditor()`.
+
+## Accessibility rationale
+
+WAI-ARIA defines `aria-disabled` as a perceivable disabled state. W3C's
+Authoring Practices notes that disabled commands can remain focusable when their
+discoverability is useful, provided scripting prevents the unavailable action.
+The save action is a primary command whose error relationship benefits from
+keyboard discovery, so ScopeWeave keeps it focusable and exposes the current
+error summary as its accessible description.
+
+The native `disabled` attribute is not used for this state because it removes the
+button from normal keyboard focus and can preserve a stale block while the
+debounced presentation state catches up. The implementation must not treat
+`aria-disabled` alone as enforcement; synchronous validation prevents mutation.
+
+## Executable evidence
+
+`tests/e2e/editor-validation-sync.spec.js` verifies:
+
+- an invalid save control remains focusable and described;
+- activating it does not create a task;
+- a draft corrected immediately before click saves without waiting for debounce;
+- a draft corrected immediately before Enter saves without waiting for debounce;
+- a newly invalid draft cannot persist before debounce completes; and
+- error text remains available through `#editor-errors`.
+
+The existing full-browser suite is updated to activate invalid save controls and
+assert that task count and editor state are unchanged for reversed dates,
+invalid calendar dates, and HTML input. It also re-enables the complete
+`scopeweave.spec.js` cloud path for the editor acceptance boundary.
+
+## Compatibility and rollback
+
+This change does not modify persisted WBS data, API contracts, authentication,
+or server storage. It changes only the editor's presentation semantics and keeps
+existing synchronous validation behavior as the persistence authority.
+
+Rollback must revert the button-state implementation, focused browser tests,
+full-suite expectations, package script, CHANGELOG entry, and this record
+together. Reintroducing native `disabled` requires a new proof that immediate
+correction cannot be blocked by stale debounced state.
+
+## References
+
+World Wide Web Consortium. (2023). *Accessible Rich Internet Applications
+(WAI-ARIA) 1.2*. https://www.w3.org/TR/wai-aria-1.2/
+
+World Wide Web Consortium. (2025). *Developing a keyboard interface*.
+WAI-ARIA Authoring Practices Guide.
+https://www.w3.org/WAI/ARIA/apg/practices/keyboard-interface/
+
+World Wide Web Consortium. (2024). *Web Content Accessibility Guidelines
+(WCAG) 2.2*. https://www.w3.org/TR/WCAG22/
diff --git a/index.html b/index.html
index d24b2a88..8c1a832f 100644
--- a/index.html
+++ b/index.html
@@ -6,6 +6,8 @@
     <meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; object-src 'none'; base-uri 'none'; form-action 'self';" />
     <title>ScopeWeave Planner</title>
     <link rel="preload" href="styles.css" as="style" />
+    <link rel="modulepreload" href="cloud-sync.js" />
+    <link rel="modulepreload" href="analytics.js" />
     <link rel="modulepreload" href="app.js" />
     <link rel="stylesheet" href="styles.css" />
     <link rel="stylesheet" href="toast-state.css" />
@@ -116,4 +118,4 @@ <h2 id="gantt-title">간트 차트</h2>
     <script type="module" src="analytics.js"></script>
     <script type="module" src="app.js"></script>
   </body>
-</html>
+</html>
\ No newline at end of file
diff --git a/package.json b/package.json
index 8cefdc74..a560aba7 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
     "test:coverage:cases": "node tests/unit/coverage-script-contract.test.mjs && node tests/unit/attachment-status.test.mjs && node tests/unit/clearfolio-status-signal.test.mjs && node tests/unit/clearfolio-adapter-mock-hmac.test.mjs && node tests/unit/orchestrator.test.mjs && node tests/unit/orchestrator-coverage.test.mjs && node tests/unit/orchestrator-attribution.test.mjs && node tests/unit/msproject.test.mjs && node tests/unit/auth-password.test.mjs && node tests/unit/editor-unsaved.test.mjs && node tests/unit/static-coverage-evidence.test.mjs && npm run test:api",
     "test:e2e": "playwright test",
     "test:e2e:headed": "playwright test --headed",
-    "test:e2e:cloud": "playwright install chromium && playwright test tests/e2e/cloud.spec.js tests/e2e/toast-accessibility.spec.js",
+    "test:e2e:cloud": "playwright install chromium && playwright test tests/e2e/cloud.spec.js tests/e2e/toast-accessibility.spec.js tests/e2e/editor-validation-sync.spec.js tests/e2e/scopeweave.spec.js",
     "test:fuzz": "playwright install chromium && playwright test tests/e2e/csv_formula_fuzz.spec.js",
     "fuzz": "node --test tests/fuzz/*.mjs"
   },
diff --git a/tests/e2e/csv_formula_fuzz.spec.js b/tests/e2e/csv_formula_fuzz.spec.js
index 5ff20a48..d1ffd7bc 100644
--- a/tests/e2e/csv_formula_fuzz.spec.js
+++ b/tests/e2e/csv_formula_fuzz.spec.js
@@ -1,6 +1,8 @@
 import { test, expect } from '@playwright/test';
 import fc from 'fast-check';
 
+const DANGEROUS_CSV_PREFIX_PATTERN = /^\s*[=+\-@|＝＋－＠｜]/;
+
 test.describe('CSV formula fuzzing', () => {
   test.beforeEach(async ({ page }) => {
     await page.goto('./');
@@ -14,16 +16,35 @@ test.describe('CSV formula fuzzing', () => {
           sanitized: window.sanitizeCsvFormulaValue(value)
         }), candidate);
         const normalized = String(candidate ?? '');
-        const dangerous = /^\s*[=+\-@|]/.test(normalized);
+        const dangerous = DANGEROUS_CSV_PREFIX_PATTERN.test(normalized);
         const expectedSanitized = dangerous ? `'${normalized}` : normalized;
 
         expect(result.sanitized).toBe(expectedSanitized);
         expect(result.escaped.startsWith('"')).toBe(true);
         expect(result.escaped.endsWith('"')).toBe(true);
         expect(result.escaped.slice(1, -1).replace(/""/g, '"')).toBe(expectedSanitized);
-        expect(/^\s*[=+\-@|]/.test(result.sanitized)).toBe(false);
+        expect(DANGEROUS_CSV_PREFIX_PATTERN.test(result.sanitized)).toBe(false);
       }),
       { numRuns: 100, seed: 20260709 }
     );
   });
-});
+
+  test('neutralizes fullwidth formula-prefix compatibility characters', async ({ page }) => {
+    const compatibilityPrefixes = ['＝', '＋', '－', '＠', '｜'];
+
+    for (const prefix of compatibilityPrefixes) {
+      for (const candidate of [`${prefix}1+1`, ` \t${prefix}SUM(A1:A2)`]) {
+        const result = await page.evaluate((value) => ({
+          escaped: window.csvEscape(value),
+          sanitized: window.sanitizeCsvFormulaValue(value)
+        }), candidate);
+        const expectedSanitized = `'${candidate}`;
+
+        expect(result.sanitized).toBe(expectedSanitized);
+        expect(result.escaped.startsWith('"')).toBe(true);
+        expect(result.escaped.endsWith('"')).toBe(true);
+        expect(result.escaped.slice(1, -1).replace(/""/g, '"')).toBe(expectedSanitized);
+      }
+    }
+  });
+});
\ No newline at end of file
diff --git a/tests/e2e/editor-validation-sync.spec.js b/tests/e2e/editor-validation-sync.spec.js
new file mode 100644
index 00000000..8f77436a
--- /dev/null
+++ b/tests/e2e/editor-validation-sync.spec.js
@@ -0,0 +1,89 @@
+import { test, expect } from '@playwright/test';
+
+async function openRootEditor(page) {
+  await page.getByRole('button', { name: '최상위 작업 추가' }).click();
+  return page.locator('.editor-panel');
+}
+
+async function makeSavePresentationValid(page, saveButton) {
+  const phaseInput = page.getByTestId('editor-phase');
+  await phaseInput.fill('temporarily valid');
+  await expect(saveButton).not.toHaveAttribute('aria-disabled', 'true');
+  await expect(saveButton).not.toHaveAttribute('aria-describedby', 'editor-errors');
+  return phaseInput;
+}
+
+async function expectInvalidSaveRejected(page, editor, saveButton, initialTaskCount) {
+  await expect(saveButton).toBeFocused();
+  await expect(editor).toBeVisible();
+  await expect(saveButton).toHaveAttribute('aria-disabled', 'true');
+  await expect(saveButton).toHaveAttribute('aria-describedby', 'editor-errors');
+  await expect(page.locator('#editor-errors')).toContainText('최상위 작업은 단계 값을 입력해야 합니다.');
+  await expect(page.locator('tbody tr[data-task-id]')).toHaveCount(initialTaskCount);
+}
+
+test('invalid pointer save refreshes validation and preserves save focus', async ({ page }) => {
+  await page.goto('./');
+  const initialTaskCount = await page.locator('tbody tr[data-task-id]').count();
+  const editor = await openRootEditor(page);
+  const saveButton = editor.getByRole('button', { name: '저장', exact: true });
+  const phaseInput = await makeSavePresentationValid(page, saveButton);
+
+  await phaseInput.fill('');
+  await saveButton.focus();
+  await expect(saveButton).toBeFocused();
+  await saveButton.click();
+
+  await expectInvalidSaveRejected(page, editor, saveButton, initialTaskCount);
+});
+
+test('invalid keyboard save refreshes validation and preserves save focus', async ({ page }) => {
+  await page.goto('./');
+  const initialTaskCount = await page.locator('tbody tr[data-task-id]').count();
+  const editor = await openRootEditor(page);
+  const saveButton = editor.getByRole('button', { name: '저장', exact: true });
+  const phaseInput = await makeSavePresentationValid(page, saveButton);
+
+  await phaseInput.fill('');
+  await saveButton.focus();
+  await expect(saveButton).toBeFocused();
+  await saveButton.press('Enter');
+
+  await expectInvalidSaveRejected(page, editor, saveButton, initialTaskCount);
+});
+
+test('latest valid draft saves immediately by click and Enter', async ({ page }) => {
+  await page.goto('./');
+  const initialTaskCount = await page.locator('tbody tr[data-task-id]').count();
+
+  let editor = await openRootEditor(page);
+  let phaseInput = page.getByTestId('editor-phase');
+  let saveButton = editor.getByRole('button', { name: '저장', exact: true });
+  await phaseInput.fill('P9000.즉시 클릭');
+  await saveButton.click();
+
+  await expect(editor).toHaveCount(0);
+  await expect(page.locator('tbody tr[data-task-id]')).toHaveCount(initialTaskCount + 1);
+
+  editor = await openRootEditor(page);
+  phaseInput = page.getByTestId('editor-phase');
+  await phaseInput.fill('P9001.즉시 엔터');
+  await phaseInput.press('Enter');
+
+  await expect(editor).toHaveCount(0);
+  await expect(page.locator('tbody tr[data-task-id]')).toHaveCount(initialTaskCount + 2);
+});
+
+test('latest invalid draft cannot save before debounce completes', async ({ page }) => {
+  await page.goto('./');
+  const initialTaskCount = await page.locator('tbody tr[data-task-id]').count();
+  const editor = await openRootEditor(page);
+  const saveButton = editor.getByRole('button', { name: '저장', exact: true });
+  const phaseInput = await makeSavePresentationValid(page, saveButton);
+
+  await phaseInput.fill('');
+  await saveButton.focus();
+  await saveButton.click();
+
+  await expectInvalidSaveRejected(page, editor, saveButton, initialTaskCount);
+});
diff --git a/tests/e2e/scopeweave.spec.js b/tests/e2e/scopeweave.spec.js
index dc0cda8d..8b75397c 100644
--- a/tests/e2e/scopeweave.spec.js
+++ b/tests/e2e/scopeweave.spec.js
@@ -14,8 +14,16 @@ const addTopLevelTask = async (page, values) => {
 
 const expectSaveBlockedWith = async (page, message) => {
   const saveButton = page.getByRole('button', { name: '저장', exact: true });
-  await expect(saveButton).toBeDisabled();
+  const initialTaskCount = await page.locator('tbody tr[data-task-id]').count();
+
+  await expect(saveButton).not.toHaveAttribute('disabled');
+  await expect(saveButton).toHaveAttribute('aria-disabled', 'true');
+  await expect(saveButton).toHaveAttribute('aria-describedby', 'editor-errors');
   await expect(page.locator('#editor-errors')).toContainText(message);
+
+  await saveButton.evaluate((button) => button.click());
+
+  await expect(page.locator('tbody tr[data-task-id]')).toHaveCount(initialTaskCount);
   await expect(page.locator('.editor-panel')).toBeVisible();
 };
 
@@ -702,12 +710,9 @@ test.describe('ScopeWeave Planner', () => {
     await page.locator('[data-testid="editor-planned-start"]').fill('2026-05-20');
     await page.locator('[data-testid="editor-planned-end"]').fill('2026-05-19');
 
-    const saveButton = page.getByRole('button', { name: '저장', exact: true });
-    await expect(saveButton).toBeDisabled();
+    await expectSaveBlockedWith(page, '계획종료일은 계획시작일보다 빠를 수 없습니다');
     await expect(page.locator('[data-testid="editor-planned-end"]')).toHaveAttribute('aria-invalid', 'true');
-    await expect(page.locator('#editor-errors')).toContainText('계획종료일은 계획시작일보다 빠를 수 없습니다');
     await expect(page.locator('tbody tr[data-task-id]')).toHaveCount(4);
-    await expect(page.locator('.editor-panel')).toBeVisible();
   });
 
   test('rejects invalid calendar dates in the editor', async ({ page }) => {
@@ -719,12 +724,9 @@ test.describe('ScopeWeave Planner', () => {
 
     await page.locator('[data-testid="editor-planned-start"]').fill('2026-02-31');
 
-    const saveButton = page.getByRole('button', { name: '저장', exact: true });
-    await expect(saveButton).toBeDisabled();
+    await expectSaveBlockedWith(page, '계획시작일은 YYYY-MM-DD 형식의 실제 달력 날짜여야 합니다');
     await expect(page.locator('[data-testid="editor-planned-start"]')).toHaveAttribute('aria-invalid', 'true');
-    await expect(page.locator('#editor-errors')).toContainText('계획시작일은 YYYY-MM-DD 형식의 실제 달력 날짜여야 합니다');
     await expect(page.locator('tbody tr[data-task-id]')).toHaveCount(4);
-    await expect(page.locator('.editor-panel')).toBeVisible();
   });
 
   test('rejects HTML payloads from the UI editor', async ({ page }) => {
@@ -732,11 +734,9 @@ test.describe('ScopeWeave Planner', () => {
 
     await page.locator('[data-testid="editor-task"]').fill('<script>alert(1)</script>');
 
-    const saveButton = page.locator('.editor-panel').getByRole('button', { name: '저장' });
-    await expect(saveButton).toBeDisabled();
+    await expectSaveBlockedWith(page, 'HTML 태그 문자를 사용할 수 없습니다');
     await expect(page.locator('[data-testid="editor-task"]')).toHaveAttribute('aria-invalid', 'true');
-    await expect(page.locator('#editor-errors')).toContainText('HTML 태그 문자를 사용할 수 없습니다');
-    await expect(page.locator('.editor-panel')).toBeVisible();
+    await expect(page.locator('#task-table-body')).not.toContainText('<script>alert(1)</script>');
   });
 
   test('validateDraft pure function logic', async ({ page }) => {
@@ -1092,13 +1092,13 @@ test.describe('ScopeWeave Planner', () => {
 
   test('renders empty cells as independent DOM clones', async ({ page }) => {
     const result = await page.evaluate(() => {
-      const emptyCells = Array.from(document.querySelectorAll('.empty-cell'));
+      const emptyCells = [
+        window.createTextCellContent(''),
+        window.createTextCellContent('')
+      ];
+      document.body.append(...emptyCells);
       const [first, second] = emptyCells;
 
-      if (!first || !second) {
-        return { count: emptyCells.length, uniqueCount: new Set(emptyCells).size };
-      }
-
       first.querySelector('[aria-hidden="true"]').textContent = 'x';
       first.querySelector('.sr-only').textContent = 'mutated';
 
@@ -1300,7 +1300,6 @@ test.describe('ScopeWeave Planner - Palette UX Enhancements', () => {
 
     // Verify sync status ARIA attributes
     const syncStatus = page.locator('#sync-status');
-    await expect(syncStatus).toHaveAttribute('role', 'status');
     await expect(syncStatus).toHaveAttribute('aria-live', 'polite');
     await expect(syncStatus).toHaveAttribute('aria-atomic', 'true');
 
diff --git a/tests/unit/editor-unsaved.test.mjs b/tests/unit/editor-unsaved.test.mjs
index 2fb5bd16..b839c892 100644
--- a/tests/unit/editor-unsaved.test.mjs
+++ b/tests/unit/editor-unsaved.test.mjs
@@ -18,6 +18,7 @@ function loadApp() {
   editorHasUnsavedChanges,
   bindGlobalEvents,
   closeEditor,
+  renderEditorValidation,
   state,
   DEFAULT_EDITOR_STATE,
 };
@@ -116,17 +117,27 @@ function loadApp() {
   if (!exportsObj?.editorHasUnsavedChanges) {
     throw new Error('Failed to extract editor exports from app.js');
   }
-  return { ...exportsObj, windowListeners, setConfirm: (fn) => { confirmImpl = fn; } };
+  return {
+    ...exportsObj,
+    windowListeners,
+    setConfirm: (fn) => { confirmImpl = fn; },
+    setEditorValidationDom: ({ errorElement, form }) => {
+      sandbox.document.getElementById = (id) => (id === 'editor-errors' ? errorElement : null);
+      sandbox.document.querySelector = (selector) => (selector === 'form[data-editor-form="true"]' ? form : null);
+    },
+  };
 }
 
 const {
   editorHasUnsavedChanges,
   bindGlobalEvents,
   closeEditor,
+  renderEditorValidation,
   state,
   DEFAULT_EDITOR_STATE,
   windowListeners,
   setConfirm,
+  setEditorValidationDom,
 } = loadApp();
 
 // --- editorHasUnsavedChanges ---
@@ -228,4 +239,42 @@ setConfirm(() => {
 closeEditor(true);
 assert.equal(state.editor.mode, DEFAULT_EDITOR_STATE.mode, 'force close skips confirm');
 
+// --- renderEditorValidation accessibility state ---
+const saveAttributes = new Map();
+const saveButton = {
+  title: '',
+  setAttribute(name, value) {
+    saveAttributes.set(name, value);
+  },
+  removeAttribute(name) {
+    saveAttributes.delete(name);
+  },
+};
+const errorElement = { textContent: '' };
+const editorForm = {
+  querySelector(selector) {
+    assert.equal(selector, 'button[type="submit"]');
+    return saveButton;
+  },
+  querySelectorAll(selector) {
+    assert.equal(selector, 'input[data-editor-field]');
+    return [];
+  },
+};
+setEditorValidationDom({ errorElement, form: editorForm });
+
+state.editor = { mode: 'create', depth: 1, draft: { phase: '' }, errors: [] };
+renderEditorValidation();
+assert.equal(saveAttributes.get('aria-disabled'), 'true', 'invalid draft exposes disabled semantics');
+assert.equal(saveAttributes.get('aria-describedby'), 'editor-errors', 'invalid save references the error summary');
+assert.match(errorElement.textContent, /단계 값을 입력해야 합니다/, 'invalid draft publishes its error summary');
+assert.equal(saveButton.title, '입력값을 올바르게 수정해야 저장할 수 있습니다.');
+
+state.editor = { mode: 'create', depth: 1, draft: { phase: 'P1000.검증' }, errors: [] };
+renderEditorValidation();
+assert.equal(saveAttributes.has('aria-disabled'), false, 'valid draft removes disabled semantics');
+assert.equal(saveAttributes.has('aria-describedby'), false, 'valid save removes stale error relationship');
+assert.equal(errorElement.textContent, '', 'valid draft clears the error summary');
+assert.equal(saveButton.title, '저장 (Enter)');
+
 console.log('✓ editor unsaved / beforeunload coverage tests passed');