feat(measurements): value-range filter on the management list

Add an optional numeric value-range filter to the measurement list:
readings whose `value` falls within `[valueMin, valueMax]`, either bound
omittable for an open-ended range. Server-authoritative — both bounds are
parsed on `listMeasurementsSchema` (coerced from the query string), an
inverted `valueMin > valueMax` returns 422, and the bounds thread into the
Prisma `where` as a `value: { gte, lte }` range on the raw per-sample list.

The filter rides a new `FilterBarNumberRange` pill that mirrors the existing
date-range control, hidden for the day-grouped and sleep-night types where
the painted value is a synthesised total rather than a stored reading.

src/app/api/measurements/route.ts

@@ -99,6 +99,8 @@ export const GET = apiHandler(async (request: NextRequest) => {
     aggregate,
     source,
     sourceEq,
+    valueMin,
+    valueMax,
     groupBy,
     dayKey,
   } = parsed.data;
@@ -116,6 +118,16 @@ export const GET = apiHandler(async (request: NextRequest) => {
     // `source=rollup` opt-in above (which selects the rollup read tier);
     // `sourceEq` narrows the plain list to one ingest source.
     ...(sourceEq && { source: sourceEq }),
+    // v1.18.5 — value-range filter (backlog G). Open-ended on either side;
+    // the validator has already rejected an inverted `valueMin > valueMax`.
+    ...(valueMin != null || valueMax != null
+      ? {
+          value: {
+            ...(valueMin != null && { gte: valueMin }),
+            ...(valueMax != null && { lte: valueMax }),
+          },
+        }
+      : {}),
     ...(from || to
       ? {
           measuredAt: {