fix(api): one helper for list pages, exact cut signal, total order

listPage (src/lib/http/list-query.ts) reads one row past the limit and
cuts it back, on top of the existing list-cap signal rather than beside
it. Every capped list now gets its page there, and every read passed to
it orders by something ending in the row id, so rows that share a sort
value cannot repeat or vanish at a page boundary.

- practitioners, vaccinations and encounters were cut at their take
  with no signal; they now answer meta.truncated and accept offset, and
  their web readers walk the pages instead of stopping at the first
- symptoms/events reported hasMore on a page that was exactly full; it
  is now true only when a row past the page exists
- the document list's hand-rolled limit + 1 goes through the helper
- security-activity answers an out-of-range limit with the 422 its
  published schema already promised instead of clamping it

list-page-guard binds every apiListSuccess route to listPage, forbids
hand-cut lists and length-derived hasMore, and requires the id
tiebreaker in every listPage read.

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

@@ -50,6 +50,7 @@ import {
   sanitiseZodIssues,
 } from "@/lib/api-response";
 import { getAiCapability } from "@/lib/ai/capabilities/gate";
+import { listPage } from "@/lib/http/list-query";
 import { prisma } from "@/lib/db";
 import { hashQueryTokens } from "@/lib/documents/content-index";
 import {
@@ -710,16 +711,17 @@ export const GET = apiHandler(async (request: Request) => {
 
   // Hardening: the list NEVER fetches the encrypted blob column — a page of
   // 50 rows would otherwise drag up to 50 × cap ciphertext bytes per request.
-  const rows = await prisma.inboundDocument.findMany({
-    where,
-    omit: { contentEncrypted: true },
-    orderBy,
-    take: limit + 1,
-    ...(cursor ? { cursor: { id: cursor }, skip: 1 } : {}),
-  });
+  const { rows: page, cap } = await listPage(limit, (take) =>
+    prisma.inboundDocument.findMany({
+      where,
+      omit: { contentEncrypted: true },
+      orderBy,
+      take,
+      ...(cursor ? { cursor: { id: cursor }, skip: 1 } : {}),
+    }),
+  );
 
-  const hasMore = rows.length > limit;
-  const page = hasMore ? rows.slice(0, limit) : rows;
+  const hasMore = cap.truncated;
   const nextCursor = hasMore ? (page[page.length - 1]?.id ?? null) : null;
 
   // Fact tallies for the whole page in ONE grouped count — no per-document