USR369 direction 08/29/26: cardio needs to be overhauled on BOTH the Android app and the HTML page. New structure: a 'Cardio Session' object that has its own name field, containing exactly 3 sub-entries -- Warmup, Main, Cooldown -- each with its own minutes, level, and heart rate fields. Heart rate specifics (units, source, manual vs synced) explicitly deferred -- 'to be discussed later', not yet specified. USR369 called this a major change, not a quick fix -- not started, not scoped in detail yet. Flagging: this overlaps with the already-open T-GYMLOGGER-REBUILD data-model layer (todo-70.md) and CC[100]'s parallel v2 rebuild work (co-owned per msg 1175) -- worth checking with CC before building either surface's cardio section in isolation, since a data-model change like this could affect the sync/schema work CC already owns. Not yet actioned.