Release prep: 0.8.0 and a Linux riscv64 release build (#669)

* Release prep: bump to 0.8.0 and add a Linux riscv64 release build

- release.yml: new `linux-riscv64` job, ported from GridCraft. It cross-compiles on
  ubuntu-24.04 against riscv64 libraries from ports.ubuntu.com (the Linux job's X11/Wayland/GL
  -dev packages plus ALSA), ships effectcraft-<v>-linux-riscv64.tar.gz, and smoke-tests
  effectcraft-cli under qemu-riscv64. The draft-release job now needs it, so its tarball is
  uploaded and covered by SHA256SUMS.txt.
- packaging/linux/package.sh: cross-compiles when CROSS_ARCH/CROSS_TARGET/CROSS_COMPILE are set
  (cargo --target, the cross strip, the EMULATOR smoke test), as GridCraft's does.
- Version 0.7.0 -> 0.8.0 (cargo xtask version set), Cargo.lock refreshed.
- README and docs/releasing.md list the riscv64 tarball.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

* Fix FreeBSD CI: pointer_wrap test harness, wasm32 target, clippy as_chunks

- pointer_wrap tests: the harnesses dropped run_ui's FullOutput with the font atlas upload still
  in textures_delta, and epaint 0.36's drop check panics on that in debug builds. Every
  pointer_wrap test failed on every platform; FreeBSD is the only CI that runs them. Clear the
  delta, as the other UI tests do.
- freebsd.yml: install wasm32-unknown-unknown in the VM. Without it the host plug-in test's build
  of examples/plugins/posterize-bands failed (E0463, no std) and the test skipped silently; now
  it builds and runs.
- media/convert.rs: chunks_exact(2) -> as_chunks::<2>() (clippy chunks_exact_to_as_chunks,
  new in Rust 1.99); same pairs, same dropped remainder.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

---------

Co-authored-by: Claude Opus 5.5 <[email protected]>

README.md

@@ -184,7 +184,7 @@ See [docs/agents.md](docs/agents.md) and [docs/control-protocol.md](docs/control
 
 Installers for each version are on the [Releases](https://github.com/storytold/effectcraft/releases)
 page: a universal macOS app; Windows MSIs and portable zips for x64, x86 and ARM64; Linux
-AppImage, Flatpak, deb, rpm and tar.gz for x86_64 and aarch64; a FreeBSD x86_64 tarball; and the
+AppImage, Flatpak, deb, rpm and tar.gz for x86_64 and aarch64, plus a riscv64 tar.gz; a FreeBSD x86_64 tarball; and the
 web build. [Downloads](#downloads) lists every file. The Windows ARM64 build runs natively on
 Windows on ARM, without x64 emulation. CI installs that MSI on Windows 11 ARM64 hardware, checks
 both programs are ARM64 and runs the command-line tool there, but it doesn't open the app's window
@@ -287,6 +287,8 @@ into a folder of your choice: `msiexec /i effectcraft-<ver>-windows-x64.msi /qn
 | Fedora/RHEL/openSUSE | `effectcraft-<ver>-linux-x86_64.rpm` | `effectcraft-<ver>-linux-aarch64.rpm` | |
 | Tarball | `effectcraft-<ver>-linux-x86_64.tar.gz` | `effectcraft-<ver>-linux-aarch64.tar.gz` | Unpack anywhere |
 
+RISC-V 64-bit: `effectcraft-<ver>-linux-riscv64.tar.gz` (tarball only; needs glibc 2.39+, e.g. Ubuntu 24.04+ or Debian 13+).
+
 **File drag-and-drop on Linux:** The current eframe/winit 0.30 native Wayland backend does not
 deliver file-hover or file-drop events. On Hyprland and other native Wayland sessions, use
 **File ▸ Import ▸ File…** (which accepts multiple files), or start EffectCraft via XWayland if