fix(documents): say when the document picker list is cut

The picker for linking documents to an illness and for choosing
documents for a share link reads the newest fifty and dropped the
route's nextCursor, so with a longer vault an older report seemed not
to exist unless one already knew to search for it. A cut list now ends
with a line that says how many are shown and that the search reaches
the rest. Paging was left out: the coach attachment picker shares the
picker's cache key with a single-page read.

src/__tests__/client-fetch-limit-guard.test.ts

@@ -83,7 +83,7 @@ const ALLOWLIST: readonly Allowed[] = [
     file: "components/documents/document-picker-sheet.tsx",
     limit: 50,
     reason:
-      "Search-backed picker (episode links and share links): the query narrows the whole document vault server-side.",
+      "Search-backed picker (episode links and share links): the query narrows the whole document vault server-side, and a cut list says so and points to the search.",
   },
   {
     file: "hooks/use-mood-day.ts",