This adds a new script `update-mirror.sh` which generates the proper
blob format for R2 (or any blob storage) to mirror all of our
dependencies.
It doesn't automate updating build.zig.zon but on an ongoing basis this
should be easy to do manually, and we can strive to automate it in the
future.
I omitted iTerm2 color themes because we auto-update that via CI and
updating all of the machinery to send it to our mirror and so on is a
pain. Additionally, this doesn't mirror transitive dependencies because
Zig doesn't have a way to fetch those from a mirror instead (unless you
pre-generate a full cache like packagers but that's not practical for
day to day development).
It's hugely beneficial just to get most of our dependencies mirrored.
This fixes a regression in 1.1.1/1.1.2 where our PACKAGING docs mention
using `fetch-zig-cache.sh` but it was removed. This commit adds it back,
generating its contents from the build.zig.zon file (via zon2nix which
we use for our Nix packaging).
For packagers, there are no dependency changes: you still need Zig and
POSIX sh. For release time, Ghostty has a new dependency on `jq` but
otherwise the release process is the same. The check-zig-cache.sh script
is updated to generate the new build.zig.zon.txt file.
- move wuffs code from src/ to pkg/
- eliminate stray debug logs
- make logs a warning instead of an error
- remove initialization of some structs to zero
