aports: extract vendor blobs before udev coldplug so first-boot audio fully works

The preset fix (6ecc1dc) makes the unit run, but multi-user is too late: the
sound card probes at ~21 s, hard-fails (-2, no retry) on the missing ACF, and
the extractor's amp rebind at ~60 s cannot re-form a card whose machine
driver already failed. Re-probing the machine driver does re-form it, but a
late-formed card has a dead capture path - the wcd9378 TX sequencer refuses
PS0 (act_ps 0x3) until the next boot. So rebinding after the fact can never
fully win; extraction has to happen before the drivers probe.

- fp6-vendor-blobs.service: DefaultDependencies=no, run after remount-fs and
  before systemd-udev-trigger, so blobs exist before module coldplug.
  multi-user stays a second Wants as a post-udev retry if the early run
  failed (by-partlabel/make-dynpart-mappings fallbacks need udev).
- aw88261-acf.manifest: add 'rebind platform sound' so the fallback path at
  least recovers playback the same boot (capture then heals on reboot).
- fp6-vendor-blobs.post-upgrade (pkgrel 1): systemctl preset + immediate
  extract, so installs of the 2026-08-24 image (unit shipped disabled, no
  version bump to deliver the preset) finally heal via plain apk upgrade.
- soc-fairphone-fp6-audio pkgrel 1: carries the manifest change.

Verified on the dev phone with the exact staged bytes (sha256-compared):
simulated fresh install (ACF removed, reboot) extracts at 13.3 s, coldplug
probes the amps at 15.1 s, card init at 20.9 s loads the ACF cleanly, and a
1 kHz speaker-to-mic loopback passes on that same first boot with zero TX
sequencer warnings; next boot takes the all-dests-present fast path in 25 ms.
Evidence: fp6 repo journal/blobs/, 2026-08-29.

Assisted-by: Claude:claude-fable-5

aports/device/fp6-vendor-blobs/fp6-vendor-blobs.post-upgrade

@@ -0,0 +1,10 @@
+#!/bin/sh
+# Re-apply the preset: images built before the preset file existed (the
+# 2026-08-24 image) shipped the unit `disabled; preset: disabled`, so an
+# upgrade must enable it or those installs never extract anything. Then
+# extract immediately rather than at the next boot (--if-device makes that
+# a quiet no-op inside build/CI chroots). A card that already hard-failed
+# this boot recovers playback via the manifest's rebind lines; capture
+# needs the next boot (journal/blobs/ 2026-08-29).
+systemctl preset fp6-vendor-blobs.service 2>/dev/null || :
+exec /usr/lib/fp6-vendor-blobs/extract --if-device