chore(measurements): drop unreferenced typesMissingCoverage and readCumulativeDaySumsBatch exports

The bucket-fresh read paths probe coverage per-type via
coverage.get(type) or rely on isFullyCovered for the all-or-nothing
fast path; the typesMissingCoverage helper had no production caller.
The cumulative-batch reader was only exercised by its own test —
the analytics A2 path took the chunked per-type findMany route in
production. Strip both and their tests.

src/lib/measurements/__tests__/rollup-read-cumulative.test.ts

@@ -24,7 +24,6 @@ import { prisma } from "@/lib/db";
 import {
   isCumulativeType,
   readCumulativeDaySums,
-  readCumulativeDaySumsBatch,
   resolveBucketSum,
 } from "../rollup-read-cumulative";
 
@@ -112,64 +111,6 @@ describe("readCumulativeDaySums", () => {
   });
 });
 
-describe("readCumulativeDaySumsBatch", () => {
-  it("groups by type and seeds empty arrays for missing types", async () => {
-    const since = new Date("2026-04-15T00:00:00.000Z");
-    mocks.findMany.mockResolvedValueOnce([
-      {
-        type: "ACTIVITY_STEPS",
-        bucketStart: new Date("2026-04-15T00:00:00.000Z"),
-        sumValue: 8120,
-        count: 4,
-        mean: 2030,
-      },
-      {
-        type: "ACTIVITY_STEPS",
-        bucketStart: new Date("2026-04-16T00:00:00.000Z"),
-        sumValue: 12480,
-        count: 5,
-        mean: 2496,
-      },
-      {
-        type: "FLIGHTS_CLIMBED",
-        bucketStart: new Date("2026-04-15T00:00:00.000Z"),
-        sumValue: 22,
-        count: 3,
-        mean: 7.33,
-      },
-    ]);
-
-    const out = await readCumulativeDaySumsBatch(
-      "user-1",
-      ["ACTIVITY_STEPS", "FLIGHTS_CLIMBED", "TIME_IN_DAYLIGHT"],
-      since,
-    );
-
-    expect(out.get("ACTIVITY_STEPS")).toHaveLength(2);
-    expect(out.get("FLIGHTS_CLIMBED")).toHaveLength(1);
-    // Type with zero rollup rows still surfaces as an empty array so
-    // the caller can avoid a `.get(...) ?? []` fallback per branch.
-    expect(out.get("TIME_IN_DAYLIGHT")).toEqual([]);
-    // Single findMany over the IN-list — replaces the per-type loop
-    // that drove the A2 cold path on Marc's tenant.
-    expect(prisma.measurementRollup.findMany).toHaveBeenCalledTimes(1);
-    const args = mocks.findMany.mock.calls[0][0];
-    expect(args.where.type).toEqual({
-      in: ["ACTIVITY_STEPS", "FLIGHTS_CLIMBED", "TIME_IN_DAYLIGHT"],
-    });
-  });
-
-  it("returns an empty map without querying when types is empty", async () => {
-    const out = await readCumulativeDaySumsBatch(
-      "user-1",
-      [],
-      new Date("2026-04-15T00:00:00.000Z"),
-    );
-    expect(out.size).toBe(0);
-    expect(prisma.measurementRollup.findMany).not.toHaveBeenCalled();
-  });
-});
-
 describe("resolveBucketSum", () => {
   it("returns sumValue when populated", () => {
     expect(

src/lib/measurements/rollup-coverage.ts

@@ -70,19 +70,6 @@ export async function probeRollupCoverage(
   return coverage;
 }
 
-/**
- * Returns the set of types the user has logged that do NOT yet have
- * DAY-rollup coverage. The bucket-fresh read paths use this to decide
- * which types still need the live aggregator branch.
- */
-export function typesMissingCoverage(coverage: RollupCoverageMap): string[] {
-  const missing: string[] = [];
-  for (const [type, hasBuckets] of coverage.entries()) {
-    if (!hasBuckets) missing.push(type);
-  }
-  return missing;
-}
-
 /**
  * Convenience — `true` when the user has at least one measurement and
  * every type with measurements also has DAY-bucket coverage. The read

src/lib/measurements/rollup-read-cumulative.ts

@@ -108,53 +108,6 @@ export async function readCumulativeDaySums(
   }));
 }
 
-/**
- * Batch read DAY buckets for several cumulative types in one round
- * trip. Eliminates the per-type chunked-findMany loop in
- * `/api/analytics` A2 for the five highest-row-count metrics on
- * Marc's tenant.
- *
- * Returns a Map keyed on `MeasurementType` so the caller can route
- * each type's rows back into the per-metric branch without scanning
- * the flat list.
- */
-export async function readCumulativeDaySumsBatch(
-  userId: string,
-  types: readonly CumulativeType[],
-  since: Date,
-): Promise<Map<CumulativeType, CumulativeDaySumRow[]>> {
-  if (types.length === 0) return new Map();
-  const rows = await prisma.measurementRollup.findMany({
-    where: {
-      userId,
-      type: { in: types as unknown as MeasurementType[] },
-      granularity: "DAY",
-      bucketStart: { gte: since },
-    },
-    orderBy: [{ type: "asc" }, { bucketStart: "asc" }],
-    select: {
-      type: true,
-      bucketStart: true,
-      sumValue: true,
-      count: true,
-      mean: true,
-    },
-  });
-  const out = new Map<CumulativeType, CumulativeDaySumRow[]>();
-  for (const t of types) out.set(t, []);
-  for (const row of rows) {
-    const bucket = out.get(row.type as CumulativeType);
-    if (!bucket) continue;
-    bucket.push({
-      bucketStart: row.bucketStart,
-      sumValue: row.sumValue,
-      count: row.count,
-      mean: row.mean,
-    });
-  }
-  return out;
-}
-
 /**
  * Resolve a per-bucket cumulative total. Reads `sumValue` when the
  * v1.4.39 writer has populated it; falls back to `mean * count` for