Add strength/stretching workouts

[rbro112]

No description provided.

[sentry]

Bug: The getWeight function incorrectly defaults to a weight of 1 for strength workouts when sets and reps are missing, instead of 0.
_{Severity: MEDIUM}

Suggested Fix

Modify the nullish coalescing operator's default value from 1 to 0 for both sets and reps within the getWeight function. The calculation should be return (item.sets ?? 0) * (item.reps ?? 0); to ensure a missing value results in a weight of 0.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: src/workouts/workout-utils.ts#L47

Potential issue: For 'strength' discipline workouts, the `getWeight` function calculates
weight using `(item.sets ?? 1) * (item.reps ?? 1)`. If both `sets` and `reps` are
undefined, which is permitted by the schema, the weight incorrectly defaults to 1. This
behavior is inconsistent with other workout disciplines, which default to a weight of 0
when their primary metrics are missing. This will cause functions like
`getTotalWeight()` to report inflated values for strength workouts that do not have
specified sets and reps.

_{Did we get this right? 👍 / 👎 to inform future reviews.}