daedalus-v4l2: 5d8b436 -> 77e14e5 — picks up #12 (LOW_DELAY) + #13 (daedalus-fourier linkage)

Daemon-only bump (no daedalus-v4l2-dkms change needed; PROTO_VERSION
stays at 0).

#12 (LOW_DELAY half-measure): daemon sets AV_CODEC_FLAG_LOW_DELAY on
the H.264 AVCodecContext so libavcodec emits frames in decode order
~99% of the time (a few stragglers at GOP boundaries when the
stream's SPS num_reorder_frames overrides the flag).  Visible
improvement vs the 2-1-4-3 pair-swap on Firefox + mpv playback;
not the permanent fix — see daedalus-v4l2#11 for the architectural
plan to substitute daedalus-fourier kernels for libavcodec's
pixel math one cycle at a time.

#13 (daedalus-fourier linkage): daemon now pkg-config-links against
the daedalus-fourier kernel library (marfrit/daedalus-fourier) and
logs substrate availability at startup.  No kernels dispatched yet
— this is the build-time foundation for the substitution work.

build-deb.sh updated to fetch + build + install daedalus-fourier
(pinned at d87239d, marfrit/daedalus-fourier PR #1) into a per-
build temp prefix before invoking the daemon's cmake, exposing it
via PKG_CONFIG_PATH.  Static-linked, so the resulting .deb has no
new runtime deps.  Requires libvulkan-dev + glslang-tools on the
CI runner.

Arch PKGBUILD bumped to the same upstream commit but Arch packaging
for daedalus-fourier itself is a follow-up; until that lands the
Arch build expects daedalus-fourier installed by the user (AUR-style).
Debian-side is end-to-end self-contained via build-deb.sh.

Refs:
  * reauktion/daedalus-v4l2#12
  * reauktion/daedalus-v4l2#13
  * reauktion/daedalus-v4l2#11
  * marfrit/daedalus-fourier#1

debian/daedalus-v4l2/build-deb.sh

@@ -11,16 +11,25 @@
 # Upstream repo: https://git.reauktion.de/reauktion/daedalus-v4l2
 set -euo pipefail
 
-# Same pin as the Arch PKGBUILD.  5d8b436 reverts PRs #7 + #8 (the
-# parking design that broke libva's 1:1 CAPTURE-buffer contract; see
-# daedalus-v4l2#9 + #10).  Tree is content-equivalent to f0d4186
-# plus PR #4 (DECODE_MODE / START_CODE menu controls — cosmetic
-# warning fix).  PROTO_VERSION drops 1 → 0; lock-step install with
-# daedalus-v4l2-dkms 0.1.0+r33+g5d8b436 REQUIRED.  Proper H.264
-# reorder fix tracked separately at daedalus-v4l2#11.
-UPSTREAM_COMMIT=5d8b4369e58ab947d1c56b1f718293c57c6065b5
-PKGVER=0.1.0+r33+g5d8b436
-PKGREL=1  # reset for new upstream pin (5d8b436 — revert parking design)
+# 77e14e5 = post-revert state plus daedalus-v4l2 PRs #12 (LOW_DELAY
+# half-measure for the H.264 display-reorder visual) and #13 (daemon
+# now links daedalus-fourier and logs substrate availability at
+# startup).  PROTO_VERSION stays at 0; daedalus-v4l2-dkms only needs
+# bumping when the kernel module changes (no kmod changes here).
+#
+# New build-dep: daedalus-fourier kernel library.  Fetched + built +
+# installed to a per-build temp prefix below, exposed to the daemon
+# cmake via PKG_CONFIG_PATH.  Static-linked into the daemon binary,
+# so the resulting .deb has no runtime dep on daedalus-fourier.
+UPSTREAM_COMMIT=77e14e5a192f0eef0b41dd1140205e29d13d4d58
+PKGVER=0.1.0+r37+g77e14e5
+PKGREL=1  # reset for new upstream pin (77e14e5 — daedalus-fourier linkage)
+
+# daedalus-fourier pin.  d87239d = marfrit/daedalus-fourier PR #1 merge
+# (install rules + pkg-config, enables this consumer to find_package
+# + link).  Bump in lockstep with the upstream daemon when daedalus-
+# fourier's API or installed shaders are changed by a new consumer.
+DAEDALUS_FOURIER_COMMIT=d87239d8172307d9a1b93c95cbed116d175b85cc
 
 HERE=$(dirname "$(readlink -f "$0")")
 
@@ -30,14 +39,37 @@ export SOURCE_DATE_EPOCH=1779231600
 work=$(mktemp -d)
 trap "rm -rf $work" EXIT
 
+# --- daedalus-fourier: fetch + build + install to per-build prefix ---
+#
+# Static-linked into the daemon, so the temp prefix is only for the
+# duration of this build script.  Requires libvulkan-dev + glslang-tools
+# on the runner (already needed for the daedalus-fourier benches).
+FOURIER_PREFIX=$work/fourier-prefix
+mkdir -p "$FOURIER_PREFIX"
+
+cd "$work"
+curl --connect-timeout 10 --max-time 600 --retry 3 --retry-delay 5 -sSLfo daedalus-fourier.tar.gz \
+    "https://git.reauktion.de/marfrit/daedalus-fourier/archive/${DAEDALUS_FOURIER_COMMIT}.tar.gz"
+tar xzf daedalus-fourier.tar.gz
+cd daedalus-fourier
+cmake -B build -G Ninja \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_INSTALL_PREFIX="$FOURIER_PREFIX"
+cmake --build build --target daedalus_core
+cmake --install build
+
+# --- daedalus-v4l2: fetch + build daemon against installed daedalus-fourier ---
+
 cd "$work"
 curl --connect-timeout 10 --max-time 600 --retry 3 --retry-delay 5 -sSLfo daedalus-v4l2.tar.gz \
     "https://git.reauktion.de/reauktion/daedalus-v4l2/archive/${UPSTREAM_COMMIT}.tar.gz"
 tar xzf daedalus-v4l2.tar.gz
 SRCDIR=daedalus-v4l2
 
-# Build daemon (CMake)
+# Build daemon (CMake) — point pkg-config at the daedalus-fourier
+# temp prefix so pkg_check_modules(DAEDALUS_FOURIER …) resolves to it.
 cd "$SRCDIR/daemon"
+PKG_CONFIG_PATH="$FOURIER_PREFIX/lib/pkgconfig" \
 cmake -B build -G Ninja \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_INSTALL_PREFIX=/usr