hakurei 0.4.6

Fixes:
- Apply patches in specified order via `internal/rosa`.
- Default to `/usr/local` prefix in `cmd/dist`.
- Skip character device nodes and print warning in `internal/pkg`.
- Unconditionally statically link C++ runtimes via `internal/rosa`.
- Print unprefixed outcome pathname to stdout in `cmd/mbf`.
- Drain optional unstructured input in `internal/rosa`.
- Use NUL for magic usage string in `command`.

Enhancements:
- Allow `nil` source in `internal/rosa`.
- Automate `/bin` symlinks in `internal/rosa`.
- Optional shallow external cure in `internal/pkg`.
- Expose cure whence in `internal/pkg`.
- Optionally force implementation entry in `internal/pkg`.
- Validate build determinism in `cmd/mbf`.
- Run `make` in hardcoded directory for build determinism in
  `internal/rosa`.
- Set `meson` timeout multiplier in `internal/rosa`.
- Consolidate cache attributes in `internal/pkg`.
- Expose preferred loadavg target to container in `internal/pkg`.
- Respect preferred loadavg target in supported build systems via
  `internal/rosa`.
- Optionally override preferred loadavg target in `cmd/mbf`.
- Migrate go toolchain to Azalea in `internal/rosa`.
- Always prepend D in `meson` helper in `internal/rosa`.
- Optional `muon` implementation for `meson` helper in `internal/rosa`.
- Allow patching output-only packages via `internal/rosa`.
- Implementation revisions in `internal/pkg`.
- Optionally set execute bit on files via `internal/pkg`.
- Make build script executable in `internal/rosa`.
- Native `zstd` and `xz` decompressor for `internal/pkg`.
- Move Gentoo stage3 bootstrap path to the `cure` command of `cmd/mbf`.
- Optionally colour output via `internal/pkg`.
- Enable output colouring in `cmd/mbf`.
- Force build system output colouring via `internal/rosa`.
- Cure entry/exit notification in `internal/pkg`.
- Set window title in `cmd/mbf`.
- Hard wrap help message flags in `command`.
- Replace readme document with license in `cmd/dist`.

Internal:
- Uncover `/tmp/` in `cmd/app`.
- Expose insecure options in `cmd/app`.
- Improve error messages in `cmd/earlyinit`.
- Updated stage0 distribution.
- Remove legacy exec helper in `internal/rosa`.
- Validate toolchain on stage 4.
- New `all` command replaces `internal/rosa` test case in `cmd/mbf`.
-----BEGIN SSH SIGNATURE-----
U1NIU0lHAAAAAQAAADMAAAALc3NoLWVkMjU1MTkAAAAg/+8EpV0uLIR+MAtm7kYw4ssYDi
TAEe6cY2wdrwBLU38AAAADZ2l0AAAAAAAAAAZzaGE1MTIAAABTAAAAC3NzaC1lZDI1NTE5
AAAAQN6MFr2p1/SOlyKIOfi9wM99bWhWJz3dIDkWOHIpjH+aR6oFtnhMcFFdEavP2JnJnJ
UnQlYeexHbNPh/NPZZzQA=
-----END SSH SIGNATURE-----