feat(api): say when a list was cut at its ceiling

A list that stops at its own take and says nothing lets the last row read
as the oldest there is. Capped lists now fetch one row past the limit and
answer meta.truncated and meta.limit on the success envelope, so data keeps
its shape. Applied to the capped lists without a total count: rhythm
events, ECG recordings, sharing grants and activity, illness episodes, side
effects, personal records, security activity, cycles, family history,
allergies and mental-health assessments. The activity feed no longer
reports a list that is exactly full as cut.

src/app/api/cycle/cycles/route.ts

@@ -12,17 +12,14 @@ import { NextRequest } from "next/server";
 import { prisma } from "@/lib/db";
 import { apiHandler, requireRecordAuth } from "@/lib/api-handler";
 import { annotate } from "@/lib/logging/context";
-import {
-  apiSuccess,
-  apiValidationError,
-  sanitiseZodIssues,
-} from "@/lib/api-response";
+import { apiValidationError, sanitiseZodIssues } from "@/lib/api-response";
 import { requireCycleEnabled } from "@/lib/cycle/gate";
 import { cycleHistoryQuerySchema } from "@/lib/validations/cycle";
 import { toMenstrualCycleDTO } from "@/lib/cycle/dto";
 import { median, mad } from "@/lib/cycle";
 import { dayDiff } from "@/lib/cycle/day-math";
 import { MIN_CYCLES_TO_PREDICT } from "@/lib/cycle/types";
+import { apiListSuccess, capRows, overfetch } from "@/lib/api/list-cap";
 
 const DEFAULT_LIMIT = 24;
 
@@ -54,11 +51,12 @@ export const GET = apiHandler(async (request: NextRequest) => {
   }
   const limit = parsed.data.limit ?? DEFAULT_LIMIT;
 
-  const rows = await prisma.menstrualCycle.findMany({
+  const found = await prisma.menstrualCycle.findMany({
     where: { userId: user.id, deletedAt: null },
     orderBy: { startDate: "desc" },
-    take: limit,
+    take: overfetch(limit),
   });
+  const { rows, cap } = capRows(found, limit);
 
   // Completed lengths (non-null lengthDays) drive the length stats.
   const lengths = rows
@@ -98,13 +96,16 @@ export const GET = apiHandler(async (request: NextRequest) => {
     meta: { returned: rows.length, regularity },
   });
 
-  return apiSuccess({
-    cycles: rows.map(toMenstrualCycleDTO),
-    stats: {
-      avgLengthDays,
-      lengthVariabilityDays,
-      avgPeriodLengthDays,
-      regularity,
+  return apiListSuccess(
+    {
+      cycles: rows.map(toMenstrualCycleDTO),
+      stats: {
+        avgLengthDays,
+        lengthVariabilityDays,
+        avgPeriodLengthDays,
+        regularity,
+      },
     },
-  });
+    cap,
+  );
 });