v0.6.0: the sky lands on your desk

The VR/AR release. Every feature here was shaped by real Quest 3 hardware testing from @tyzbit, who also recorded the attached demo video: orbiting live traffic, free-flying through it, and dropping the scope onto actual furniture with AR place mode.

Highlights

• AR place mode: look at a surface, pull the trigger, the airspace parks there. WebXR hit-test snaps it to tables, desks, and beds.
• Free-fly, tuned by feel: first-person yaw, deliberate height control, zoom that anchors on what you're looking at. "Years of video games finally paying off."
• Wrist menu with full settings parity: three pages generated from a declarative spec, guarded by a test so no future setting can silently miss the in-headset UI.
• Fat lines: altitude lines and trails at real pixel widths scaled to your render resolution. No more 1px shimmer at 5040x2640 per eye.
• Honest quality readout: the settings panel now reports the actual per-eye resolution your headset granted.
• Stereo mode for WayVR / crossed-eye viewers: billboard and exit button rendered in both eyes.
• Mobile bottom sheet: the aircraft detail card no longer eats the map on phones. Fixed-height sheet, internal scroll, photo docked beside the airframe data at its natural aspect.

Full details in CHANGELOG.md. The attached mp4 is the full-length demo; a shorter cut is embedded in the README.