Merge pull request 'daemon: dlopen Kwiboo fork's soname 62 (FFmpeg 8.1 at /opt/fourier)' (#16) from noether/daemon-dlopen-kwiboo-soname62 into main

Reviewed-on: #16

daemon/src/ffmpeg_loader.c

@@ -11,14 +11,31 @@
 #include <dlfcn.h>
 
 /*
- * SONAME versions match Debian Trixie / FFmpeg 7.1.3 today.  If
- * the system FFmpeg changes major, the daemon needs a rebuild;
- * we could add fallback paths (.so.60, .so.59, ...) but for
- * Phase 8.3 the pinned version is fine.
+ * SONAME versions match the Kwiboo ffmpeg-v4l2-request-fourier
+ * fork (FFmpeg 8.1) installed at the /opt/fourier prefix.  The
+ * fourier campaign's ld.so.conf.d/fourier.conf entry resolves
+ * these sonames from /opt/fourier/lib via the ld cache, so
+ * dlopen-by-soname works without LD_LIBRARY_PATH wrappers.
+ *
+ * Switched from Debian-stock soname 61/61/59 (FFmpeg 7.1.3) at
+ * 2026-05-21 to land daedalus-fourier kernel substitution into
+ * the production decode path via patches in the Kwiboo fork
+ * (see daedalus-v4l2#11 substitution arc): we own the fork
+ * source in marfrit-packages, so we can layer NEON-DSP
+ * substitution patches there for libavcodec/aarch64/h264dsp_init
+ * → daedalus_recipe_dispatch_* thunks.  The Debian-stock 7.1.3
+ * is built outside the marfrit-packages source tree, which
+ * would have made layering substitution patches awkward.
+ *
+ * Note: libavutil bumps soname 59 → 60 between FFmpeg 7.1 and
+ * 8.1; libavformat + libavcodec each bump 61 → 62.  The public
+ * API surface the daemon uses (avcodec_send_packet /
+ * receive_frame / AVCodecContext flags / AVFrame fields) is
+ * stable across the bump.
  */
-#define LIBAVFORMAT_SONAME	"libavformat.so.61"
-#define LIBAVCODEC_SONAME	"libavcodec.so.61"
-#define LIBAVUTIL_SONAME	"libavutil.so.59"
+#define LIBAVFORMAT_SONAME	"libavformat.so.62"
+#define LIBAVCODEC_SONAME	"libavcodec.so.62"
+#define LIBAVUTIL_SONAME	"libavutil.so.60"
 
 /*
  * Resolve a symbol from a dlopen'd handle.  Logs the failure