refactor(rollups): move measurement-rollups under src/lib/rollups umbrella

Creates the new src/lib/rollups/ aggregator directory and relocates
the main measurement rollup module:

- src/lib/measurements/rollups.ts → src/lib/rollups/measurement-rollups.ts
- src/lib/measurements/__tests__/rollups.test.ts →
  src/lib/rollups/__tests__/measurement-rollups.test.ts

Every importer of @/lib/measurements/rollups is rewritten to
@/lib/rollups/measurement-rollups. The orphan sibling reference inside
src/lib/measurements/rollup-read.ts (still in its old home until the
next batch) is promoted to the @/lib alias so the chain keeps
typechecking through the in-flight move.

Pure relocation — no behaviour change, no exported-surface change. The
umbrella exists so the rollup contract is discoverable from a single
directory before the iOS sprint locks the boundary.

src/app/api/admin/backups/[id]/restore/route.ts

@@ -48,7 +48,7 @@ import {
   recomputeUserMedicationCompliance,
   MEDICATION_COMPLIANCE_BACKFILL_DAYS,
 } from "@/lib/medications/compliance-rollups";
-import { recomputeUserRollups } from "@/lib/measurements/rollups";
+import { recomputeUserRollups } from "@/lib/rollups/measurement-rollups";
 
 export const dynamic = "force-dynamic";
 

src/app/api/admin/rollups/recompute/route.ts

@@ -38,7 +38,7 @@ import { annotate } from "@/lib/logging/context";
 import {
   enqueueBootTimeRollupBackfill,
   recomputeUserRollups,
-} from "@/lib/measurements/rollups";
+} from "@/lib/rollups/measurement-rollups";
 
 interface RecomputeBody {
   userId?: string;

src/app/api/analytics/route.ts

@@ -15,7 +15,7 @@ import type {
 } from "@/generated/prisma/client";
 import { measurementTypeEnum } from "@/lib/validations/measurement";
 import { pickCanonicalSourceRows } from "@/lib/analytics/source-priority";
-import { ensureUserRollupsFresh } from "@/lib/measurements/rollups";
+import { ensureUserRollupsFresh } from "@/lib/rollups/measurement-rollups";
 import { probeRollupCoverage } from "@/lib/measurements/rollup-coverage";
 import { computeBpInTargetFastPath } from "@/lib/analytics/bp-in-target-fast-path";
 import { computeUserHealthScoreFastPath } from "@/lib/analytics/health-score-fast-path";

src/app/api/import/__tests__/route.test.ts

@@ -31,10 +31,10 @@ vi.mock("@/lib/logging/context", () => ({
 // assert that the import path now folds the persistent rollup tier
 // for each touched (type, day). Mood rollup mock stays no-op because
 // the existing v1.4.39 W-MOOD hook already covers the moodlog branch.
-vi.mock("@/lib/measurements/rollups", async () => {
+vi.mock("@/lib/rollups/measurement-rollups", async () => {
   const actual = await vi.importActual<
-    typeof import("@/lib/measurements/rollups")
-  >("@/lib/measurements/rollups");
+    typeof import("@/lib/rollups/measurement-rollups")
+  >("@/lib/rollups/measurement-rollups");
   return {
     ...actual,
     recomputeBucketsForMeasurement: vi.fn().mockResolvedValue(undefined),
@@ -49,7 +49,7 @@ import { NextRequest } from "next/server";
 import { POST } from "../route";
 import { checkRateLimit } from "@/lib/rate-limit";
 import { prisma } from "@/lib/db";
-import { recomputeBucketsForMeasurement } from "@/lib/measurements/rollups";
+import { recomputeBucketsForMeasurement } from "@/lib/rollups/measurement-rollups";
 
 beforeEach(() => {
   vi.resetAllMocks();

src/app/api/import/route.ts

@@ -21,7 +21,7 @@ import { recomputeUserMoodRollups } from "@/lib/mood/rollups";
 import {
   collapseToTypeDayKeys,
   recomputeBucketsForMeasurement,
-} from "@/lib/measurements/rollups";
+} from "@/lib/rollups/measurement-rollups";
 import type { MeasurementType } from "@/generated/prisma/client";
 
 // Derived from canonical enum so round-trip export → import covers every

src/app/api/measurements/[id]/route.ts

@@ -10,7 +10,7 @@ import {
 } from "@/lib/api-response";
 import { updateMeasurementSchema } from "@/lib/validations/measurement";
 import { invalidateUserMeasurements } from "@/lib/cache/invalidate";
-import { recomputeBucketsForMeasurement } from "@/lib/measurements/rollups";
+import { recomputeBucketsForMeasurement } from "@/lib/rollups/measurement-rollups";
 import { Prisma } from "@/generated/prisma/client";
 import { NextRequest } from "next/server";
 

src/app/api/measurements/__tests__/range-aggregation-route.test.ts

@@ -30,10 +30,10 @@ vi.mock("@/lib/db", () => ({
 // v1.4.39.2 — the rollup branch's coverage-mismatch fallback may call
 // `recomputeUserRollups` inline. Mock it so tests can assert whether
 // the inline fold fired without exercising the real populator.
-vi.mock("@/lib/measurements/rollups", async () => {
+vi.mock("@/lib/rollups/measurement-rollups", async () => {
   const actual = await vi.importActual<
-    typeof import("@/lib/measurements/rollups")
-  >("@/lib/measurements/rollups");
+    typeof import("@/lib/rollups/measurement-rollups")
+  >("@/lib/rollups/measurement-rollups");
   return {
     ...actual,
     recomputeBucketsForMeasurement: vi.fn().mockResolvedValue(undefined),
@@ -61,7 +61,7 @@ vi.mock("next/headers", () => ({
 import { GET } from "../route";
 import { prisma } from "@/lib/db";
 import { getSession } from "@/lib/auth/session";
-import { recomputeUserRollups } from "@/lib/measurements/rollups";
+import { recomputeUserRollups } from "@/lib/rollups/measurement-rollups";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },

src/app/api/measurements/batch/route.ts

@@ -41,7 +41,7 @@ import { invalidateUserMeasurements } from "@/lib/cache/invalidate";
 import {
   recomputeBucketsForMeasurement,
   collapseToTypeDayKeys,
-} from "@/lib/measurements/rollups";
+} from "@/lib/rollups/measurement-rollups";
 import { Prisma, type MeasurementType } from "@/generated/prisma/client";
 
 // v1.4.25 W16c — historical-backfill threshold for PR push

src/app/api/measurements/by-external-ids/route.ts

@@ -35,7 +35,7 @@ import { invalidateUserMeasurements } from "@/lib/cache/invalidate";
 import {
   recomputeBucketsForMeasurement,
   collapseToTypeDayKeys,
-} from "@/lib/measurements/rollups";
+} from "@/lib/rollups/measurement-rollups";
 
 const MAX_BATCH_ENTRIES = 500;
 

src/app/api/measurements/route.ts

@@ -30,7 +30,7 @@ import {
   recomputeBucketsForMeasurement,
   collapseToTypeDayKeys,
   recomputeUserRollups,
-} from "@/lib/measurements/rollups";
+} from "@/lib/rollups/measurement-rollups";
 import { NextRequest } from "next/server";
 import type {
   MeasurementType,