feat: prefer specific OS, gate .git on unpacker, probe zst/7z, deploy script

[coolaj86]

Summary

Five related changes that together make the resolver pick the right binary instead of accidentally installing source archives, git clones, or just dropping versions on the floor:

1. _webi/builds-cacher.js — _enumerateTriplets: prefer specific OS/arch over ANYOS/ANYARCH.
2. _webi/builds-cacher.js — getSortedFormats: gate .git on the caller's formats list, mirroring .tar.xz, .tar.zst, .zip, .7z.
3. webi/webi.sh: probe unzstd/zstd alongside the existing git/unxz/unzip/tar probes.
4. webi/webi-pwsh.ps1: replace the hardcoded formats=zip,exe,tar,git TODO with Get-Command probes for git, zstd, 7z.
5. _scripts/deploy-webid: rsync deploy with submodule precondition, _cache symlink restore, anchored worker pkill, smoke tests.
6. _webi/build-classifier: bump submodule to pull in webi-build-classifier#21 — fixes maybeInstallable rejecting any package version ending in .1.

⚠️ Dependency

Commit 6 bumps the submodule to a SHA on webinstall/webi-build-classifier#21's feature branch. That PR should land first so the bumped SHA is reachable from webi-build-classifier's main. Without #21, serviceman v1.0.1 (and any other patch.1 version of a source-archive-only package) is still silently dropped by the classifier and the user gets v1.0.0 instead.

Motivation

serviceman (and any package with a */*/git fallback alongside per-OS binaries) was resolving to git instead of the binary, even on hosts with git absent:

$ curl -A 'aarch64/unknown Darwin/24.2.0 libc' \
       https://next.webi.sh/api/installers/serviceman@stable.sh
WEBI_EXT='git'

Two distinct bugs:

A. Triplet ordering — _enumerateTriplets produced ANYOS-* triplets before specific OS triplets:

1: ANYOS-ANYARCH-none      ← serviceman's */*/git matches here
...
7: posix_2017-ANYARCH-none ← serviceman's tar.gz/zip is here

findMatchingPackages returned the git-only triplet first. The .git-as-unpacker gate (commit 2) is correct but downstream — by the time selectPackage is called the wrong triplet has already been picked.

B. Classifier silent drop — Triplet.maybeInstallable checked build.download.endsWith(ext) against TERMS_EXTS_NON_BUILD which contains .1 (intended for manpage.1). GitHub source-archive URLs of the form .../tarball/v1.0.1 end in .1, so the classifier silently rejected the entire v1.0.1 release. Fixed in webi-build-classifier#21 by checking build.name instead.

Behavior

After this PR + the build-classifier PR:

• serviceman macos/linux any host (default formats): v1.0.1/zip (was git → would fail without git).
• serviceman Windows: still no Windows binary in the cache (Go-cache content gap, not addressed by this PR — needs therootcompany/serviceman fetched alongside bnnanet/serviceman).
• vim-commentary (only-git package): unchanged. selectPackage's packages.length === 1 early return covers single-option triplets.
• webi <pkg> on a host with zstd: now sends ?formats=...,zst.
• webi-pwsh.ps1 on Windows: probes git/zstd/7z via Get-Command.

Test plan

• npm test passes.
• PR branch deployed to both beta.webi.sh and next.webi.sh. Verified /api/installers/serviceman@stable.sh:
  • macos arm64 → v1.0.1/zip (was v1.0.1/git pre-PR; would be v1.0.0/zip without commit 6).
  • linux amd64/arm64/musl → same (v1.0.1/zip).
  • windows amd64 → v0.9.8/git (still broken — cache gap, separately tracked).
• vim-commentary still resolves to git correctly.
• Reviewer: check no regression on a binary-package (e.g. node, jq, bat, fd) at the resolved version/ext level.

Notes

• Companion to fix(builds-cacher): coalesce concurrent getPackages for same name #1073 (race-condition fix in the same file).
• _scripts/deploy-webid includes a submodule precondition that catches "I forgot to git submodule update --init" before the rsync silently pushes an empty _webi/build-classifier/. That scenario broke deploys repeatedly during this PR's testing.

Commits

c69359f chore(build-classifier): bump to fix-maybe-installable-version-suffix
d9c315d fix(builds-cacher): enumerate specific OS/arch before ANYOS/ANYARCH
19673d8 feat(scripts): add deploy-webid with submodule precondition
2d1c082 feat(webi): probe zst as unpacker; properly probe formats in webi-pwsh
28cd129 ref(builds-cacher): gate .git on client-provided unpacker

Depends on: webinstall/webi-build-classifier#21