PiZZa v0.4.0 — pizero convergence + Pi Zero W image

PizzaShell on the upstream-clean Zephyr tree, plus a Pi Zero W image.

What's new since v0.3

• Pi Zero W image. PizzaShell now ships a second binary for the
  original 2017 Pi Zero W (BCM2835, ARM1176, ARMv6) — console-only
  (Display / Storage / Wi-Fi all -- by design). One PizzaShell source,
  both boards.
• Upstream-clean Zephyr tree. v0.3 was built against the pizza
  Zephyr branch (legacy bcm2835_property VC mailbox API). v0.4.0
  builds against the pizero branch — upstream Zephyr main plus the
  rpi_zero_2w board + ARMv6 + BCM driver work prepared for upstream PR.
  New rpi_fw firmware API throughout; chained multi-tag
  rpi_fw_fb_setup helper for the VideoCore framebuffer; DWC2 USB PHY
  power-on quirk ported to rpi_fw_transfer(RPI_FW_TAG_SET_POWER_STATE).
• Real EDID monitor detection. pizza now probes
  RPI_FW_TAG_GET_EDID_BLOCK and reports Display: (no monitor detected)
  when nothing is on the HDMI cable. v0.3 reported HDMI 640x480 (the
  VC fallback surface when hdmi_force_hotplug=1 is on).
• DNS resolution. net dns google.com resolves from the shell on
  the 2W.

Flash

Standard PiZZa workflow — see the README
for SD imaging via PINN and install-to-sdcard.sh.

Two binaries:

• pizza-v0.4.0-rpi_zero_w.bin — original Pi Zero W (BCM2835, ARMv6)
• pizza-v0.4.0-rpi_zero_2w.bin — Pi Zero 2 W (BCM2710, AArch64)