Reborn startup latency correction

The owner-installed audio candidate was inspected read-only after the report that the startup splash remained visible for too long. The retained boot trace showed the splash visible at 0.828 s, Y2ROOT completing its handoff at 12.246 s, and the splash releasing/presenting at 52.047/52.060 s.

The running Reborn process was created near 19.5 s, but its first structured application record appeared near 41.0 s. Its executable directly required all six FFmpeg shared libraries, so the ARM dynamic loader performed their cold relocation and constructor work before main. The remaining application trace took about 3.5 s to reach the scan worker and 6.2 s to create the Mali400 EGL context; first frame presentation followed at about 11.0 s from the Reborn session start. A dirty FAT volume was also reported by the kernel, but it is an independent storage-health issue rather than the Reborn loader delay.

The correction keeps FFmpeg 9.0.1 authoritative and moves the media membrane behind a lazy shared boundary. The reborn ELF has no FFmpeg DT_NEEDED entries; /usr/lib/reborn/libreborn_media.so carries the six FFmpeg SONAMEs and is loaded on the first decoder, artwork, conversion, crossfade or runtime component request. Reborn now records millisecond startup phases, opens the GPU context before the library scan, and starts from S05reborn after S02y2-data. D-Bus, BlueZ, wpa_supplicant and connectivity remain worker dependencies with retry behavior, so early UI startup does not wait for radios.

Host and ARM validation completed for the candidate source: the workspace tests pass, the reborn-media crate passes strict Clippy, the ARM cross build passes with the production Buildroot SDK, the Buildroot package installs the shared membrane, and pinned QEMU runs the installed ARM binaries with the actual FFmpeg 9.0.1 runtime manifest. The next startup timing measurement requires the owner to install this root-only candidate; no physical retest is claimed by QEMU or host ELF inspection.