diff --git a/e2e/documents-ai.spec.ts b/e2e/documents-ai.spec.ts
new file mode 100644
index 000000000..e73689ecc
--- /dev/null
+++ b/e2e/documents-ai.spec.ts
@@ -0,0 +1,337 @@
+/**
+ * Document vault — the P2 AI-assist + content-search acceptance suite.
+ *
+ * Pins the review-first contract (a suggestion prefills an editable field and
+ * is only ever written on an explicit save — never auto-committed), the
+ * session-only summary panel (transient, carrying the "not saved · not a
+ * diagnosis" note), whole-word content search reaching a body-only word through
+ * the real blind-token GIN union, the corpus "index all" backfill CTA, the calm
+ * provider-unavailable pointer (no provider → no assist button, a settings
+ * link instead), and the text-mode image-only refusal that fires client-side
+ * before any OCR/upload work.
+ *
+ * The seeded demo user has NO AI provider, so the unavailable state is the
+ * default; the enabled states are driven by `page.route` mocks of `usage` +
+ * the OCR capability probe + the AI endpoints. Content search uses NO mock — it
+ * seeds a real `document_content_index` row (`ensureVaultAiFixture`) and drives
+ * the real list union.
+ */
+import { expect, test, type Page } from "@playwright/test";
+
+import { STORAGE_STATE_PATH } from "./setup/global-setup";
+import {
+  ensureVaultFixture,
+  ensureVaultAiFixture,
+  AI_PROBE_DOC_ID,
+  CONTENT_DOC_ID,
+  CONTENT_BODY_WORD,
+} from "./setup/vault-fixture";
+
+/** The vault usage DTO the UI reads before offering upload + AI affordances. */
+function usageBody(overrides: {
+  assistAvailable: boolean;
+  contentIndex: { enabled: boolean; indexedCount: number; totalCount: number };
+}) {
+  return {
+    data: {
+      usedBytes: 4096,
+      quotaBytes: 1_073_741_824,
+      maxFileBytes: 26_214_400,
+      acceptedExtensions: [".pdf", ".png", ".jpg", ".jpeg", ".webp"],
+      linkedEpisodes: [],
+      assistAvailable: overrides.assistAvailable,
+      contentIndex: overrides.contentIndex,
+    },
+    error: null,
+  };
+}
+
+/** Fulfil the envelope shape the client unwraps (`(await res.json()).data`). */
+async function fulfilJson(
+  route: Parameters<Parameters<Page["route"]>[1]>[0],
+  body: unknown,
+) {
+  await route.fulfill({
+    status: 200,
+    contentType: "application/json",
+    body: JSON.stringify(body),
+  });
+}
+
+/**
+ * Mock the AI-availability surface: `usage` (assist + content-index flags) and
+ * the OCR capability probe (transport mode). Endpoints (suggest/summary/reindex)
+ * are mocked per-test on top of this.
+ */
+async function mockAiEnabled(
+  page: Page,
+  opts: {
+    mode: "vision" | "text";
+    pdfSupported?: boolean;
+    contentIndex?: {
+      enabled: boolean;
+      indexedCount: number;
+      totalCount: number;
+    };
+  },
+): Promise<void> {
+  const contentIndex = opts.contentIndex ?? {
+    enabled: true,
+    indexedCount: 0,
+    totalCount: 1,
+  };
+  await page.route("**/api/documents/inbound/usage", (route) =>
+    fulfilJson(route, usageBody({ assistAvailable: true, contentIndex })),
+  );
+  await page.route("**/api/labs/ocr/capability", (route) =>
+    fulfilJson(route, {
+      data: {
+        available: true,
+        mode: opts.mode,
+        reason: null,
+        pdfSupported: opts.pdfSupported ?? opts.mode === "vision",
+      },
+      error: null,
+    }),
+  );
+}
+
+test.describe("document vault — AI assist + content search", () => {
+  test.use({ storageState: STORAGE_STATE_PATH });
+
+  test.beforeAll(async () => {
+    await ensureVaultFixture();
+    await ensureVaultAiFixture();
+  });
+
+  // ── (a) Review-first assist: prefill → edit → save, nothing auto-committed ──
+
+  test("assist prefills an editable draft that only saves on commit", async ({
+    page,
+  }) => {
+    await mockAiEnabled(page, { mode: "vision" });
+
+    const suggestedTitle = `Suggested lab report ${Date.now()}`;
+    await page.route(
+      `**/api/documents/inbound/${AI_PROBE_DOC_ID}/suggest`,
+      (route) =>
+        fulfilJson(route, {
+          data: {
+            suggestions: {
+              title: suggestedTitle,
+              kind: "LAB_RESULT",
+              documentDate: "2025-03-03",
+            },
+          },
+          error: null,
+        }),
+    );
+
+    // Count PATCH writes to this document — a review-first draft must not fire
+    // one until the user commits.
+    let patchCount = 0;
+    page.on("request", (req) => {
+      if (
+        req.method() === "PATCH" &&
+        req.url().includes(`/api/documents/inbound/${AI_PROBE_DOC_ID}`)
+      ) {
+        patchCount += 1;
+      }
+    });
+
+    await page.goto(`/documents?doc=${AI_PROBE_DOC_ID}`);
+    const sheet = page.getByRole("dialog");
+    await expect(sheet).toBeVisible();
+
+    const suggest = sheet.locator('[data-slot="assist-suggest"]');
+    await expect(suggest).toBeEnabled();
+    await suggest.click();
+
+    const review = sheet.locator('[data-slot="assist-suggestion-review"]');
+    await expect(review).toBeVisible();
+    await expect(
+      review.getByText("AI suggestion — review before saving"),
+    ).toBeVisible();
+
+    // Applying the title seeds the EDITABLE field only — no write yet.
+    await review.getByRole("button", { name: "Use title" }).click();
+    const titleInput = sheet.locator("#document-title-input");
+    await expect(titleInput).toHaveValue(suggestedTitle);
+    expect(patchCount).toBe(0);
+
+    // Commit (blur/Enter) → the write fires exactly once, carrying the title.
+    const saved = page.waitForRequest(
+      (req) =>
+        req.method() === "PATCH" &&
+        req.url().includes(`/api/documents/inbound/${AI_PROBE_DOC_ID}`),
+    );
+    await titleInput.press("Enter");
+    const savedReq = await saved;
+    expect(JSON.parse(savedReq.postData() ?? "{}").title).toBe(suggestedTitle);
+    expect(patchCount).toBe(1);
+  });
+
+  // ── (b) Session-only summary: transient, note present, closing discards ──
+
+  test("summary panel is transient and labelled not-saved / not-a-diagnosis", async ({
+    page,
+  }) => {
+    await mockAiEnabled(page, { mode: "vision" });
+    const summaryText = "A chest imaging report issued by a radiology clinic.";
+    let summaryCalls = 0;
+    await page.route(
+      `**/api/documents/inbound/${AI_PROBE_DOC_ID}/summary**`,
+      (route) => {
+        summaryCalls += 1;
+        return fulfilJson(route, {
+          data: { summary: summaryText },
+          error: null,
+        });
+      },
+    );
+
+    await page.goto(`/documents?doc=${AI_PROBE_DOC_ID}`);
+    const sheet = page.getByRole("dialog");
+    await expect(sheet).toBeVisible();
+
+    await sheet.getByRole("button", { name: "Summarise" }).click();
+    const panel = sheet.locator('[data-slot="document-summary-panel"]');
+    await expect(panel).toBeVisible();
+    await expect(panel.getByText(summaryText)).toBeVisible();
+    await expect(
+      panel.getByText(
+        "Not saved · not a diagnosis. Shown once for this view only.",
+      ),
+    ).toBeVisible();
+    expect(summaryCalls).toBe(1);
+
+    // Closing discards — the panel is gone and nothing lingers.
+    await panel.getByRole("button", { name: "Hide" }).click();
+    await expect(panel).not.toBeVisible();
+  });
+
+  // ── (c) Content search reaches a BODY-ONLY word through the token union ──
+
+  test("content search finds a word that lives only in the document body", async ({
+    page,
+  }) => {
+    await page.goto("/documents");
+    await expect(
+      page.getByRole("heading", { name: "Documents" }),
+    ).toBeVisible();
+
+    // The word is absent from every title/filename — the only route is the
+    // real blind-token union over the seeded content index.
+    await page
+      .getByRole("searchbox", { name: "Search documents" })
+      .fill(CONTENT_BODY_WORD);
+
+    const card = page.getByRole("button", { name: "Open Radiology note" });
+    await expect(card).toBeVisible({ timeout: 10_000 });
+    await expect(page).toHaveURL(new RegExp(`q=${CONTENT_BODY_WORD}`));
+
+    // The matched card advertises its searchable body.
+    const searchable = page
+      .locator('[data-slot="document-card"]', { hasText: "Radiology note" })
+      .locator('[data-slot="document-searchable"]');
+    await expect(searchable).toBeVisible();
+
+    // Sanity: the word really is absent from the short fields (server-side
+    // confirmation the union — not an ILIKE — did the work).
+    const viaApi = await page.request.get(
+      `/api/documents/inbound?q=${CONTENT_BODY_WORD}&limit=10`,
+    );
+    const body = await viaApi.json();
+    const hit = body.data.documents.find(
+      (d: { id: string }) => d.id === CONTENT_DOC_ID,
+    );
+    expect(hit).toBeTruthy();
+    expect(`${hit.title} ${hit.filename}`.toLowerCase()).not.toContain(
+      CONTENT_BODY_WORD,
+    );
+  });
+
+  // ── (d) Corpus "index all" backfill CTA ──────────────────────────────────
+
+  test("the index-all CTA enqueues the corpus backfill", async ({ page }) => {
+    await mockAiEnabled(page, {
+      mode: "vision",
+      contentIndex: { enabled: true, indexedCount: 1, totalCount: 10 },
+    });
+    let reindexCalls = 0;
+    await page.route("**/api/documents/inbound/reindex", (route) => {
+      reindexCalls += 1;
+      return fulfilJson(route, { data: { enqueued: 5 }, error: null });
+    });
+
+    await page.goto("/documents");
+    const hint = page.locator('[data-slot="content-search-hint"]');
+    await expect(hint).toBeVisible();
+    const indexAll = page.locator('[data-slot="content-index-all"]');
+    await expect(indexAll).toBeVisible();
+    await indexAll.click();
+
+    await expect(
+      page.getByText("Indexing 5 document(s) in the background."),
+    ).toBeVisible();
+    expect(reindexCalls).toBe(1);
+  });
+
+  // ── (e) No-provider degradation: calm pointer, no assist button ──────────
+
+  test("with no provider the detail sheet shows a calm settings pointer", async ({
+    page,
+  }) => {
+    // No mocks — the seeded demo user has no AI provider configured.
+    await page.goto(`/documents?doc=${AI_PROBE_DOC_ID}`);
+    const sheet = page.getByRole("dialog");
+    await expect(sheet).toBeVisible();
+
+    await expect(
+      sheet.locator('[data-slot="assist-unavailable"]'),
+    ).toBeVisible();
+    await expect(
+      sheet.getByRole("link", { name: "Open AI settings" }),
+    ).toBeVisible();
+    // The action button is absent — the endpoint would 422, so the UI never
+    // offers it.
+    await expect(sheet.locator('[data-slot="assist-suggest"]')).toHaveCount(0);
+  });
+
+  // ── (f) Text-mode refuses a non-image before any OCR/upload ──────────────
+
+  test("text-mode assist refuses a PDF client-side before any request", async ({
+    page,
+  }) => {
+    await mockAiEnabled(page, { mode: "text", pdfSupported: false });
+    let suggestCalls = 0;
+    await page.route(
+      `**/api/documents/inbound/${AI_PROBE_DOC_ID}/suggest`,
+      (route) => {
+        suggestCalls += 1;
+        return fulfilJson(route, {
+          data: {
+            suggestions: { title: null, kind: null, documentDate: null },
+          },
+          error: null,
+        });
+      },
+    );
+
+    await page.goto(`/documents?doc=${AI_PROBE_DOC_ID}`);
+    const sheet = page.getByRole("dialog");
+    await expect(sheet).toBeVisible();
+
+    const suggest = sheet.locator('[data-slot="assist-suggest"]');
+    await expect(suggest).toBeEnabled();
+    await suggest.click();
+
+    // The PDF is refused locally (tesseract reads images only) — the error
+    // shows and the server suggest route is never called.
+    await expect(
+      sheet.getByText("Local OCR reads images only — not this file."),
+    ).toBeVisible();
+    await page.waitForTimeout(300);
+    expect(suggestCalls).toBe(0);
+  });
+});
diff --git a/e2e/setup/vault-fixture.ts b/e2e/setup/vault-fixture.ts
index 9cd1538ba..31320e09c 100644
--- a/e2e/setup/vault-fixture.ts
+++ b/e2e/setup/vault-fixture.ts
@@ -23,7 +23,13 @@
  * same date and link. `seedNamespaceDocs` adds disposable per-test
  * namespaces (bulk flows) that never collide with the doctor-flow corpus.
  */
-import { createCipheriv, createHash, randomBytes } from "node:crypto";
+import {
+  createCipheriv,
+  createHash,
+  createHmac,
+  hkdfSync,
+  randomBytes,
+} from "node:crypto";
 
 import pg from "pg";
 
@@ -68,6 +74,68 @@ function encryptBinary2(plaintext: Buffer): Buffer {
   ]);
 }
 
+/**
+ * Encrypt a plaintext string into the `encrypt()`-string-as-UTF-8 Bytes shape
+ * the content index stores `text_encrypted` in (`<keyId>.<base64(iv|tag|ct)>`
+ * → UTF-8 bytes). Mirrors src/lib/crypto.ts `encrypt` + the coach bytes codec.
+ */
+function encryptStringToBytes(plaintext: string): Buffer {
+  const { id, key } = resolveActiveKey();
+  const iv = randomBytes(12);
+  const cipher = createCipheriv("aes-256-gcm", key, iv);
+  const enc = Buffer.concat([cipher.update(plaintext, "utf8"), cipher.final()]);
+  const tag = cipher.getAuthTag();
+  const payload = Buffer.concat([iv, tag, enc]).toString("base64");
+  return Buffer.from(`${id}.${payload}`, "utf8");
+}
+
+// ─── Blind content-index tokens (mirrors src/lib/documents/content-index) ────
+//
+// HKDF-derived index subkey off the ACTIVE encryption key + domain label, then
+// each normalised token HMAC-SHA256'd and truncated to a 16-char hex tag. The
+// server hashes a search query the same way, so a body-only word seeded here is
+// findable through the real GIN union without ever storing the word in clear.
+
+const CONTENT_INDEX_INFO = "healthlog:document-content-index:v1";
+
+function indexSubkey(): Buffer {
+  const { key } = resolveActiveKey();
+  return Buffer.from(
+    hkdfSync("sha256", key, new Uint8Array(0), CONTENT_INDEX_INFO, 32),
+  );
+}
+
+/** Tokenise like the server: NFKD de-accent, lowercase, alnum runs, len 3..64.
+ *  The seeded words are deliberately non-stopwords, so the stopword drop the
+ *  server also applies is a no-op here and the tag sets match exactly. */
+function tokenise(text: string): string[] {
+  const normalised = text
+    .normalize("NFKD")
+    .replace(/\p{Diacritic}/gu, "")
+    .toLowerCase();
+  const seen = new Set<string>();
+  for (const raw of normalised.split(/[^\p{L}\p{N}]+/u)) {
+    const token = raw.trim();
+    if (token.length < 3 || token.length > 64) continue;
+    seen.add(token);
+  }
+  return [...seen];
+}
+
+function tokeniseAndHash(text: string): string[] {
+  const subkey = indexSubkey();
+  const hashes = new Set<string>();
+  for (const token of tokenise(text)) {
+    hashes.add(
+      createHmac("sha256", subkey)
+        .update(token, "utf8")
+        .digest("hex")
+        .slice(0, 16),
+    );
+  }
+  return [...hashes];
+}
+
 // ─── Deterministic tiny documents ───────────────────────────────────────────
 
 /** Minimal single-page PDF; `marker` lands in a comment so every doc's bytes
@@ -96,6 +164,15 @@ function tinyPng(marker: string): Buffer {
 
 export const KNIE_EPISODE_ID = "e2evaultknie000000000001";
 export const MRT_DOC_ID = "e2evaultmrt0000000000001";
+/** A stored PDF the AI-assist specs drive (mocked provider); title/kind are
+ *  bland so an applied suggestion is visibly different. */
+export const AI_PROBE_DOC_ID = "e2evaultaiprobe000000001";
+/** A stored document whose searchable body word lives ONLY in its content
+ *  index — never in the title or filename — so content search is the only
+ *  route to it. */
+export const CONTENT_DOC_ID = "e2evaultcontent00000001";
+/** The whole word that appears only in `CONTENT_DOC_ID`'s indexed body. */
+export const CONTENT_BODY_WORD = "pneumothorax";
 /** Filing date of the MRT report — "last autumn" relative to the fixture. */
 const MRT_DOC_DATE = "2025-10-14";
 
@@ -263,6 +340,69 @@ export async function ensureVaultFixture(): Promise<void> {
   }
 }
 
+/**
+ * Seed the P2 AI-assist + content-search fixtures:
+ *   - a bland PDF the assist / summary specs drive against a mocked provider;
+ *   - a document whose only searchable word (`CONTENT_BODY_WORD`) lives in its
+ *     blind content index, not its title/filename, so content search is the
+ *     sole route to it — exercising the real GIN token union end-to-end.
+ * Idempotent (fixed ids upserted); safe to call from every spec's beforeAll.
+ */
+export async function ensureVaultAiFixture(): Promise<void> {
+  const url = process.env.DATABASE_URL;
+  if (!url) throw new Error("[vault-fixture] DATABASE_URL is not set");
+  const pool = new pg.Pool({ connectionString: url });
+  try {
+    const userId = await getUserId(pool);
+
+    await upsertDocs(pool, userId, [
+      {
+        id: AI_PROBE_DOC_ID,
+        kind: "OTHER",
+        title: "AI probe report",
+        filename: "ai-probe-report.pdf",
+        mimeType: "application/pdf",
+        documentDate: "2026-04-02",
+        bytes: tinyPdf(AI_PROBE_DOC_ID),
+      },
+      {
+        // Title + filename deliberately omit CONTENT_BODY_WORD.
+        id: CONTENT_DOC_ID,
+        kind: "DOCTOR_REPORT",
+        title: "Radiology note",
+        filename: "radiology-note.pdf",
+        mimeType: "application/pdf",
+        documentDate: "2026-03-10",
+        bytes: tinyPdf(CONTENT_DOC_ID),
+      },
+    ]);
+
+    // Seed CONTENT_DOC_ID's blind content index: the body word is only findable
+    // via the token union. The plaintext text is stored encrypted (never read
+    // by the search path) purely to mirror a real index row.
+    const body = `Chest imaging report. Findings consistent with ${CONTENT_BODY_WORD}. No pleural effusion noted.`;
+    await pool.query(
+      `INSERT INTO document_content_index
+        (id, document_id, user_id, text_encrypted, search_tokens, source,
+         provider_type, tokenizer_version, created_at, updated_at)
+       VALUES ($1, $2, $3, $4, $5, 'vision', NULL, '1', NOW(), NOW())
+       ON CONFLICT (document_id) DO UPDATE SET
+         text_encrypted = EXCLUDED.text_encrypted,
+         search_tokens = EXCLUDED.search_tokens,
+         updated_at = NOW()`,
+      [
+        "e2evaultcidx0000000000001",
+        CONTENT_DOC_ID,
+        userId,
+        encryptStringToBytes(body),
+        tokeniseAndHash(body),
+      ],
+    );
+  } finally {
+    await pool.end();
+  }
+}
+
 /**
  * Seed a disposable, namespaced batch of OTHER-kind PDF documents for the
  * bulk-flow specs (`title`/`filename` carry the prefix so a search filter