MOB-30: refresh mobile_surface_matrix.md (magnetometer/compass/orientation-lock/BLE)

[GenericJam]

Refreshes the hand-maintained capability matrix, which had drifted behind shipped work. Closes MOB-30.

Rows corrected (verified against current code, not just the issue text)

Row	Was	Now	Evidence
Screen orientation lock	❌	✅ ✓/✓	Mob.Device.lock_orientation/1 + unlock_orientation/0 (device.ex)
Bluetooth Low Energy	❌	🟡 ✓/✓	MobBluetooth.Le (mob_bluetooth 0.3.0) — GATT peripheral role (advertise + notify + receive writes), iOS + Android; BLE central/scan is future
Magnetometer	❌	✅ ✓/✓	Mob.Motion :magnetometer — µT mag + fused heading, shipped 0.7.14 (MOB-6)
Compass / heading	❌	✅ ✓/✓	fused heading via the same path

Also corrected the Bluetooth Classic note: mob_bluetooth has no Hid sub-module (only Hfp/Spp), and clarified its central/host, Android-only scope.

Sweep

Per the issue's "sweep every ❌/🟡 row" ask, the remaining missing rows were checked against current lib/ and cross-referenced with the MOB backlog — sensors (barometer/proximity/ambient/pedometer), NFC, WiFi, screen brightness, keep-awake, network state, speech-recognition, contacts/calendar, etc. all still map to open MOB issues and remain absent from core. No further changes.

Docs-only; no code paths touched.

🤖 Generated with Claude Code

[GenericJam]

Reviewed — LGTM, endorse merge. (Same account, so posting as a comment rather than a formal approval.)

Verified every changed row against origin/master + the mob_bluetooth repo, not just the PR text:

• Orientation lock ✅ — Mob.Device.lock_orientation/1 (device.ex:189) + unlock_orientation/0 (199); native on both platforms (iOS g_locked_orientation_mask + supported-orientations/geometry, Android nif_device_lock_orientation → setRequestedOrientation). iOS ✓ / Android ✓ is correct.
• BLE 🟡 — MobBluetooth.Le in mob_bluetooth 0.3.0, GATT peripheral role, cross-platform (iOS CBPeripheralManager + Android); central/scan is future. Accurate.
• Bluetooth Classic — confirmed mob_bluetooth/lib/mob_bluetooth/ has only hfp.ex / spp.ex / le.ex (no hid.ex), so dropping the "Hid" claim is a genuine correction.
• Magnetometer / compass ✅ — matches the 0.7.14 Mob.Motion :magnetometer contract, including "keys present only when requested."

Nice catch on the orientation-lock row (stale but not even in the issue title) and the Hid error. Sweep of the remaining ❌ rows is sound — they all still map to open MOB backlog issues.

Non-blocking nit: Mob.Motion.start(:magnetometer, ...) is loose vs the real start(socket, sensors: [:magnetometer]), but it just mirrors the existing accel/gyro rows — pre-existing doc style, fine to leave.

Good to merge and close MOB-30.