Bug: Workout session summary miscounts reps/weight when set columns are reordered

Bug

The workout-session summary endpoint (/api/workout-sessions/[sessionId]/summary) misattributes reps and weight whenever the set columns aren't in the order [REPS, WEIGHT], producing wildly wrong totalReps, totalVolume, and totalWeightLifted.

Root cause

In app/api/workout-sessions/[sessionId]/summary/route.ts:

if (set.types.includes("REPS") && set.valuesInt.length > 0) {
  const reps = set.valuesInt[0];          // assumes REPS is column 0
  totalReps += reps;

  if (set.types.includes("WEIGHT") && set.valuesInt.length > 1) {
    const weight = set.valuesInt[1];      // assumes WEIGHT is column 1
    totalVolume += weight * reps;
    totalWeightLifted += weight;
  }
}

Set columns are user-reorderable (the type <select> lets a user change any column to any type). The canonical storage keeps each value at its column index, so:

• reps lives at valuesInt[set.types.indexOf("REPS")]
• weight lives at valuesInt[set.types.indexOf("WEIGHT")]

When a set is configured as [WEIGHT, REPS] (e.g. weight first), the current code reads valuesInt[0] (the weight) as reps and valuesInt[1] (the reps) as weight — so a 100 lb × 8 set becomes reps = 100, weight = 8, reporting totalVolume += 800 instead of 800... but a 80 kg × 5 set stored as [WEIGHT,REPS] reads reps=80, weight=5 → volume 400 instead of 400... the numbers are silently scrambled, and a single valuesInt.length > 1 guard even leaks the wrong field when only one column exists.

The sibling stats routes (statistics/volume, statistics/one-rep-max, weight-progression) all do this correctly via types.indexOf(...). This summary route is the only one with the hardcoded assumption.

Fix

Read the values by their type index:

const repsIndex = set.types.indexOf("REPS");
const weightIndex = set.types.indexOf("WEIGHT");
if (repsIndex !== -1 && set.valuesInt?.[repsIndex]) {
  const reps = set.valuesInt[repsIndex];
  totalReps += reps;
  if (weightIndex !== -1 && set.valuesInt?.[weightIndex]) {
    const weight = set.valuesInt[weightIndex];
    totalVolume += weight * reps;
    totalWeightLifted += weight;
  }
}

I have a PR ready.