aports/fp6-device-tweaks: stop the modem-gnss 30 s restart loop

pmOS's modem-gnss.service runs two qmicli calls, and the second --
--loc-set-nmea-types=all -- can never succeed on this modem: the LOC
engine answers QMI error 94 'NotSupported' to both get and set. That is
a permanent capability gap, not the boot race Restart=on-failure exists
for, so the unit failed and restarted every 30 s for the whole uptime
(restart counter 25 after 13 minutes; 165 over one evening). Its
StartLimit does not stop it either: 10 restarts at RestartSec=30 span
~303 s, just past StartLimitInterval=300.

Ship a drop-in that tolerates that one command's failure. The boot-race
retry stays armed -- a LOC service that is genuinely not up still fails
the first ExecStart. Nothing is lost: ModemManager issues its own
set-NMEA-types and takes the same 94 regardless, and location comes from
the Position Report path our modemmanager patches add.

Byte-identical to the drop-in verified on the dev phone (sha256
b0b5f71b0f25c3c5a8fc9e926f187412a6711da95f773234065f37ddcc1d3c6d):
across a reboot the unit runs once, Result=success, 0 restarts.

Assisted-by: Claude:claude-opus-5

aports/device/fp6-device-tweaks/APKBUILD

@@ -9,9 +9,12 @@
 #    trigger; iio-sensor-proxy must use its poll backend or auto-rotate is dead
 #  - iio-sensor-proxy restart drop-in: revives it after the known boot-time
 #    libssc crash on unconfigured SSC
+#  - modem-gnss drop-in: this modem's LOC engine answers QMI 94 NotSupported
+#    to NMEA-type config, which is permanent, so pmOS's modem-gnss.service
+#    retried it every 30 s forever (its StartLimit never trips)
 maintainer="Jorijn van der Graaf <jorijnvdgraaf@catcrafts.net>"
 pkgname=fp6-device-tweaks
-pkgver=3
+pkgver=4
 pkgrel=0
 pkgdesc="Fairphone 6 device-critical system configuration"
 url="https://forgejo.catcrafts.net/Catcrafts/fp6-img"
@@ -26,6 +29,7 @@ source="
 	inv-icm42600.conf
 	81-fp6-accel-poll.rules
 	iio-sensor-proxy-restart.conf
+	modem-gnss-nmea-optional.conf
 "
 
 package() {
@@ -39,10 +43,13 @@ package() {
 		"$pkgdir"/etc/udev/rules.d/81-fp6-accel-poll.rules
 	install -Dm644 "$srcdir"/iio-sensor-proxy-restart.conf \
 		"$pkgdir"/etc/systemd/system/iio-sensor-proxy.service.d/restart.conf
+	install -Dm644 "$srcdir"/modem-gnss-nmea-optional.conf \
+		"$pkgdir"/etc/systemd/system/modem-gnss.service.d/10-nmea-types-optional.conf
 }
 
 sha512sums="
 5e60fef47cb09cec7cab73464183dfd9e9cb32cebd1d20a67922c10c5a747eca8d106b66737d06af5c5c162a6baf37ab62a82709cc20911044face100d482919  inv-icm42600.conf
 cc13f6abc4538fef976c59893992dd2c193cd0eac5da37a9fb01ba421b3ba8ff303aa438ec2fe4d10f50165f90be211d4b2c39dc6ef58d0d320fba8182ccf287  81-fp6-accel-poll.rules
 1800ad5c11b4e38c10b0c72b2392a6dc978a4e37bcd964182adb90d7d9aa7afc74acf102e2051dbf864021c05821f683af8943e2729e1eaa195856a0bd635e09  iio-sensor-proxy-restart.conf
+8fec832be59ca616d3e6a4c0a5ef8067d25f767c79155d8b0ef5761b8d21532932235a3236807305937029efe6255a16696d05523e3e654e2dc2212a281fe12c  modem-gnss-nmea-optional.conf
 "

aports/device/fp6-device-tweaks/modem-gnss-nmea-optional.conf

@@ -0,0 +1,14 @@
+# FP6 (milos): the modem LOC engine does not implement NMEA-type configuration
+# at all -- both --loc-get-nmea-types and --loc-set-nmea-types return
+# QMI protocol error (94) NotSupported. That is a permanent engine capability,
+# not a boot race, so the unit's Restart=on-failure retried it every 30 s
+# forever (StartLimitBurst=10/StartLimitInterval=300 never trips: 10 restarts
+# at RestartSec=30 span ~303 s > 300 s). NMEA sentences are delivered by the
+# engine regardless -- on-device fixes carry RMC.
+#
+# Tolerate the failure of that one command; a genuinely-not-up LOC service
+# still fails the first ExecStart and keeps the intended boot-race retry.
+[Service]
+ExecStart=
+ExecStart=qmicli -d qrtr://0 --loc-set-engine-lock=mt
+ExecStart=-qmicli -d qrtr://0 --loc-set-nmea-types=all