Implement robust WebGL fallback for 3D rendering

[sensei-hacker]

Summary

Adds automatic fallback from hardware to software WebGL rendering with graceful degradation when WebGL is completely unavailable.

⚠️ Testing Required

This PR needs testing in Windows VM after CI builds complete:

• Test with GPU drivers missing/outdated
• Test in Remote Desktop / VNC session
• Test with hardware acceleration disabled in Options
• Verify fallback messages appear correctly
• Verify no crashes occur

Problem

The configurator had WebGL detection code but crashed when WebGL was unavailable:

• When renderer.getContext('webgl') failed, renderer stayed undefined
• Code then tried to call renderer.setSize() → crash: Cannot read property 'setSize' of undefined
• The existing "fallback" model was never used because the app crashed before loading it

Solution

Implemented a 3-tier progressive fallback:

1. Tier 1: Try hardware-accelerated WebGL (best performance)
2. Tier 2: Try software-rendered WebGL with failIfMajorPerformanceCaveat: false (slower but compatible)
3. Tier 3: Show user-friendly message and provide no-op functions (graceful degradation)

Changes

• Add tryCreateWebGLContext() helper with 3-tier fallback
• Try hardware WebGL, then software WebGL, then graceful disable
• Show user-friendly error messages when 3D unavailable with actionable troubleshooting steps
• Provide no-op render3D() and resize3D() functions to prevent crashes
• Add console logging for WebGL rendering method detection

Testing Completed

Linux testing:

• ✅ Normal operation (hardware WebGL available) - PASSED
• ✅ WebGL completely unavailable (forced fail) - PASSED, shows fallback message

Benefits

• Prevents crashes when WebGL unavailable in Setup and Magnetometer tabs
• Improves UX for users with GPU driver issues
• Better support for VM environments and Remote Desktop
• Clear guidance for users on how to resolve issues

Files Modified

• tabs/setup.js: Robust WebGL detection for 3D aircraft model
• tabs/magnetometer.js: Robust WebGL detection for compass visualization

[Jetrell]

I tested it on an older laptop with older drivers.
With 3D acceleration disabled in the application options. It works the same as it does with the present RC3 release. Any extra load placed on the graphic hardware, above what was there before the ESM updates prior to RC1, is still there with this build.

When 3D acceleration disable is unchecked. This is the effect.

However the configurator doesn't sit there is an internal "waiting for data" state, like it did before this PR. If 3D acceleration disabled wasn't checked in the application options.

I forwarded the build link to some others that had asked about this issue last month. I'll see what they have to say when they get back to me.

[sensei-hacker]

Thanks, Jetrell! The screenshot shows the desired behavior if WebGL isn't available (via hardware acceleration or software emulation).