Guard log stream setup against missing TOC variables

[ataffanel]

Problem

Several async log streaming methods (_stream_motors in FlightTab, _stream_battery in MainUI, _stream_loop in PoseLogger) add log variables unconditionally via block.add_variable(). If a variable is missing from the firmware's log TOC (e.g. due to firmware version differences or custom builds), this will raise an exception inside a create_task() coroutine, which can crash the tab or silently kill the streaming task.

Currently only supervisor.info has a TOC guard:

if self.LOG_NAME_SUPERVISOR_INFO in log.names():
    await block.add_variable(self.LOG_NAME_SUPERVISOR_INFO)

But other variables like sys.canfly, stabilizer.thrust, motor.m1-m4, pm.vbat, pm.state, and the stateEstimate.* pose variables are added without checking.

Suggestion

Add log.names() checks before adding variables, or wrap the setup in a try/except that gracefully disables the corresponding UI elements when variables are unavailable. This would make the client more robust against firmware variations.

Affected locations

• src/cfclient/ui/tabs/FlightTab.py — _stream_motors()
• src/cfclient/ui/main.py — _stream_battery()
• src/cfclient/ui/pose_logger.py — _stream_loop()

Context

Raised during Copilot review of PR #792.

[evanofficial]

taking this one — going to mirror the existing supervisor.info guard across the three streams you flagged, so missing TOC vars get skipped with a warning instead of nuking the task