feat(documents): expose content-index provenance on the document DTO

Surface the content-search index's source (vision vs local extraction) on
the list + detail DTO so the vault UI can tell an AI-read document from a
locally-indexed one. Threads the source through both read paths and the
serialisers, regenerates the OpenAPI contract, and adds a narrowing helper
for the free-String column.

src/app/api/documents/inbound/[id]/route.ts

@@ -27,7 +27,10 @@ import { serialiseDocumentDetail } from "@/lib/documents/store";
 import { annotate } from "@/lib/logging/context";
 import { requireModuleEnabled } from "@/lib/modules/gate";
 import { checkRateLimit, rateLimitHeaders } from "@/lib/rate-limit";
-import { documentUpdateSchema } from "@/lib/validations/inbound-documents";
+import {
+  documentUpdateSchema,
+  toContentIndexSource,
+} from "@/lib/validations/inbound-documents";
 import type { Prisma } from "@/generated/prisma/client";
 
 type RouteParams = { params: Promise<{ id: string }> };
@@ -80,7 +83,7 @@ export const GET = apiHandler(
       loadConditionLinks(user.id, [document.id]),
       prisma.documentContentIndex.findUnique({
         where: { documentId: document.id },
-        select: { id: true },
+        select: { source: true },
       }),
     ]);
 
@@ -95,6 +98,7 @@ export const GET = apiHandler(
         document.facts,
         links.get(document.id) ?? [],
         contentIndex !== null,
+        toContentIndexSource(contentIndex?.source),
       ),
     );
   },
@@ -173,7 +177,13 @@ export const PATCH = apiHandler(
       omit: { contentEncrypted: true },
       include: { facts: { orderBy: { createdAt: "asc" } } },
     });
-    const links = await loadConditionLinks(user.id, [document.id]);
+    const [links, contentIndex] = await Promise.all([
+      loadConditionLinks(user.id, [document.id]),
+      prisma.documentContentIndex.findUnique({
+        where: { documentId: document.id },
+        select: { source: true },
+      }),
+    ]);
 
     const touched = [
       ...Object.keys(data),
@@ -199,6 +209,8 @@ export const PATCH = apiHandler(
         document,
         document.facts,
         links.get(document.id) ?? [],
+        contentIndex !== null,
+        toContentIndexSource(contentIndex?.source),
       ),
     );
   },

src/app/api/documents/inbound/route.ts

@@ -55,6 +55,7 @@ import { checkRateLimit, rateLimitHeaders } from "@/lib/rate-limit";
 import {
   documentCreateSchema,
   documentListQuerySchema,
+  toContentIndexSource,
 } from "@/lib/validations/inbound-documents";
 import type { Prisma } from "@/generated/prisma/client";
 
@@ -506,15 +507,16 @@ export const GET = apiHandler(async (request: Request) => {
     page.map((d) => d.id),
   );
 
-  // Which of the page's documents have a content index (drives `hasContentIndex`
-  // + the re-index affordance). One indexed grouped query; never the ciphertext.
-  const indexedIds = new Set<string>();
+  // Which of the page's documents have a content index (drives the searchable
+  // status + the provenance the UI reads to tell an AI-read document from a
+  // locally-indexed one). One grouped query; never the ciphertext.
+  const indexSources = new Map<string, string>();
   if (page.length > 0) {
     const indexed = await prisma.documentContentIndex.findMany({
       where: { userId: user.id, documentId: { in: page.map((d) => d.id) } },
-      select: { documentId: true },
+      select: { documentId: true, source: true },
     });
-    for (const row of indexed) indexedIds.add(row.documentId);
+    for (const row of indexed) indexSources.set(row.documentId, row.source);
   }
 
   annotate({
@@ -533,7 +535,8 @@ export const GET = apiHandler(async (request: Request) => {
         doc,
         factCounts.get(doc.id) ?? { factCount: 0, pendingCount: 0 },
         linkMap.get(doc.id) ?? [],
-        indexedIds.has(doc.id),
+        indexSources.has(doc.id),
+        toContentIndexSource(indexSources.get(doc.id)),
       ),
     ),
     nextCursor,