Why does the duplicate-workout-name error differ by provider?

Error detail strings differ across providers because Terra normalises some providers' error conditions into a consistent message, while passing others through…

Error detail strings differ across providers because Terra normalises some providers' error conditions into a consistent message, while passing others through raw from the provider API.

Raw passthrough strings are not versioned and can change whenever a provider updates their API, so matching on them exactly is fragile.

Use per-provider substring matching as the defensive approach until consistent normalised messages are applied across all providers.