Merge branch 'fix/v1437-review' into release/v1.43.7

# Conflicts:
#	src/app/api/analytics/route.ts

src/lib/validations/measurement.ts

@@ -589,7 +589,7 @@ export const listMeasurementsSchema = z
     // Omitting `aggregate` keeps the raw wire shape (iOS contract); the
     // chart-data client must opt in explicitly.
     aggregate: z.enum(["raw", "daily", "weekly", "monthly"]).optional(),
-    // v1.4.36 W1 — opt-in source switch for daily-aggregate reads. When
+    // v1.4.36 — opt-in source switch for daily-aggregate reads. When
     // `source=rollup` + `aggregate=daily`, the route reads from the
     // persistent `measurement_rollups` DAY buckets instead of running a
     // live `date_trunc` GROUP BY scan over the raw `measurements` table.
@@ -612,7 +612,7 @@ export const listMeasurementsSchema = z
     // `value: { gte, lte }` range. Server-authoritative; validated min<=max.
     valueMin: z.coerce.number().finite().optional(),
     valueMax: z.coerce.number().finite().optional(),
-    // v1.4.37 W7c — list-view "one row per day" mode for cumulative
+    // v1.4.37 — list-view "one row per day" mode for cumulative
     // types (steps, active energy, distance, flights, daylight). When
     // `groupBy=day` is set and `type` is a cumulative HK type, the route
     // returns one synthesised row per user-TZ day with `value` = SUM
@@ -623,18 +623,18 @@ export const listMeasurementsSchema = z
     // picks the page's local days in Postgres and reports the distinct-day
     // count as `meta.total` (#1245).
     groupBy: z.enum(["day"]).optional(),
-    // v1.4.37 W7c — drill-down to per-sample rows for a single day in
+    // v1.4.37 — drill-down to per-sample rows for a single day in
     // the user's IANA timezone. Format `YYYY-MM-DD`; the route resolves
     // the day boundary against the user's `User.timezone`. Used by the
     // expandable list row to reveal the chunks that contributed to the
     // collapsed daily total.
     //
-    // v1.4.37 W10 — a drill-down returns one bounded page rather than a
+    // v1.4.37 — a drill-down returns one bounded page rather than a
     // cursor, so it refuses a non-zero `offset`.
     dayKey: z
       .string()
       .regex(/^\d{4}-\d{2}-\d{2}$/, "dayKey must be YYYY-MM-DD")
-      // v1.4.37 W10 — a `YYYY-MM-DD` string can satisfy the regex while
+      // v1.4.37 — a `YYYY-MM-DD` string can satisfy the regex while
       // still being an impossible calendar date (`2026-02-30`,
       // `2026-13-01`). `new Date("2026-02-30T00:00:00Z")` silently
       // overflows to March 2, so the drill-down would return rows from
@@ -665,6 +665,19 @@ export const listMeasurementsSchema = z
       "limit must be <= 1000 when dayKey is set; drill-down responses are capped at 1000 rows",
     path: ["limit"],
   })
+  // A value range filters single readings, and a day-grouped row is the sum
+  // of a whole day: filtering its readings would return partial days summed
+  // as if they were whole. The combination has no honest answer, so it is
+  // refused rather than served.
+  .refine(
+    ({ groupBy, valueMin, valueMax }) =>
+      groupBy !== "day" || (valueMin == null && valueMax == null),
+    {
+      message:
+        "valueMin / valueMax filter single readings and cannot be combined with groupBy=day",
+      path: ["groupBy"],
+    },
+  )
   // v1.18.5 — an inverted value range (`valueMin > valueMax`) is a client
   // bug, not an empty result set; reject it at the validator with a 422 so
   // the filter UI can surface the mismatch instead of silently returning