# v1.45.0: workout duplicate window

A correctness change, not a speed one; the request benchmark does not read
workouts, so there is no latency row for it.

Before: two copies of one session were collapsed only when both starts fell
in the same fixed five-minute clock slot (`floor(start / 5 min)`). A pair 30 s
apart that straddled a slot boundary stayed two workouts in the list, the
batch write, the calendar, strain and the Coach.

After: per user and sport, sorted by start, a workout joins the open cluster
while it starts less than five minutes after the cluster's first start.

Proof (`src/lib/measurements/__tests__/pick-canonical-workout-rows.property.test.ts`,
against the previous picker kept as `pick-canonical-workout-rows.legacy.ts`):

| property | inputs |
| --- | --- |
| same rows as the fixed slots wherever no pair within five minutes straddles a slot boundary, three ladders | 4,000 generated inputs, over 1,000 comparable |
| same strain impulses as before on those inputs | 2,000 generated inputs, over 500 comparable |
| two sources' copies collapse at any offset under five minutes (the old picker missed a share) | 3,000 random offsets |
| five minutes or more apart never collapse | 2,000 |
| a uniform shift of every start keeps the picked set | 1,500 |
| a row of workouts four minutes apart does not chain | fixed case |

One existing case changed its expectation: three runs at 08:04, 08:08 and
08:12 used to stay three because they sat in three slots; 08:08 is now the
08:04 run from a lower-ranked source (four minutes apart), and 08:12 stays.