v0.2.35

App 0.2.41: extension-declared views, and a build() that depends on the
image alone so a view that cannot build genuinely means the image is
defective. Faults are published to /run/instrument-cluster/unhealthy.

The health check now gates mark-good on that marker. Without it the
registry's fail-open behaviour would leave a broken update marked good —
the dashboard still comes up, display/GPU/wlan/input all pass — and the
slot would never roll back.

post-build.sh now fails the build when the app is not in the rootfs.
Buildroot will happily produce a complete, bootable image with a package
missing; that shipped a 1.7 GB image which booted to nothing while every
other check passed.

Kernel: drops drivers for hardware this image never has (CAN, camera,
NFC, raw flash, IR, and DRM/framebuffer/touch controllers for panels and
touch chips other than the three DSI panels and two touch chips shipped).
DRM_VC4, SND and SND_SOC stay enabled — DRM_VC4 depends on the latter two
for HDMI audio, and losing them drops the display controller silently.

The Pi 4's kernel feature decisions move into the same shared fragments
the Pi 5 uses, so the two boards cannot drift apart on them again.

Verified on a local Pi 4 build: DRM_VC4=y, all three panel drivers and
the Goodix touch present, CAN/NFC/BT off, module tables populated (1063
deps, 8046 aliases), app 0.2.41 in the rootfs.