Arch and libc fallbacks are not universal — they depend on the OS,
the package, and even the version. ARM64 on macOS/Windows can run
x64 (Rosetta/emulation) but not on Linux. Musl can be static or
dynamically linked depending on the package version. Windows GNU
may or may not need mingw.
These rules belong in per-installer config, not in shared types.
platlatest stays as a simple fact store (triplet → version).
Resolution with fallbacks will be the caller's job.
Prefer latest version over best CPU match. An amd64v4 machine gets
v2.0.0 (baseline only) instead of v1.0.0 (which had a v4 build)
because recency beats specificity.
- buildmeta: add amd64v2/v3/v4 micro-levels, ArchFallbacks, LibcFallbacks
- classify: detect micro-arch levels, treat Windows "arm" as ARM64
- platlatest: add Resolve() that walks fallback chains picking newest
classify extracts OS, arch, libc, and format from release asset
filenames using regex pattern matching with priority ordering
(x86_64 before x86, arm64 before armv7, etc.).
platlatest tracks the newest release version per build target
(OS+arch+libc triplet) to handle the common case where Windows
or macOS releases lag behind Linux by several versions.
