Custom webhook payload templates

Hi :)

Currently the JSON shape is fixed per the app's internal schema (snake_case, flat arrays like steps/heart_rate/etc). Several self-hosted platforms (e.g. Open Wearables) expect a different shape — nested under a data object, camelCase fields, type-tagged unified records array. Right now getting data into these requires running a separate translation/relay service.

Would it be possible to add an optional custom payload template per webhook — e.g. a simple key-mapping or JSON template config (similar to how some webhook apps let you define {{field}} placeholders) — so the app could emit an already-reshaped payload for specific target platforms, without needing a middleman service?

Even just documenting a few common target schemas (Open Wearables, Home Assistant, etc.) as presets would help a lot.