fix: wahoo setSimGrade sent before setSimMode (KICKR CORE race condition)

[cagnulein]

Problem

On KICKR CORE (and similar Wahoo devices), setSimGrade was being sent to the trainer before setSimMode had ever been sent.

Root cause

stateChanged() subscribes to all notifiable/indicatable characteristics across all BLE services. On a KICKR CORE this amounts to 17 descriptor writes (notificationSubscribed = 17). The descriptorWritten callbacks arrive slowly from the BLE stack — in the reported log only 9 of the 17 had arrived by the time Zwift sent its first indoor bike simulation parameters FTMS command (~30 seconds after connection).

Since notificationSubscribed never reached 0, initRequest was never set to true, so the update() init block (which sends unlock → setSimMode → setWheelCircumference) never ran.

Meanwhile Zwift's FTMS write flows through a direct signal/slot path:
CharacteristicWriteProcessor2AD9 → changeSlope → inclinationChanged → setSimGrade
…which bypasses initRequest entirely, sending setSimGrade to a trainer that had never received setSimMode.

Fix

Subscribe only to CyclingPowerMeasurement during stateChanged() — at most 1 descriptor write — so descriptorWritten fires almost immediately and the init sequence (including setSimMode) completes before Zwift can send the first slope command.

A fallback is also added: if no CyclingPowerMeasurement subscription was established at all, initRequest is set directly from stateChanged() so the init always runs.

This is a minimal, targeted fix. A previous attempt (PR #4530, closed as wontfix) addressed the same issue with additional unrelated changes; this PR contains only the essential change.

Test plan

• Connect KICKR CORE and verify setSimMode appears in the log before the first setSimGrade
• Ride in Zwift: resistance/slope changes should work correctly from the start
• Verify no regression for KICKR SNAP and KICKR BIKE (ERG mode, gear mode)

🤖 Generated with Claude Code

[stale]

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