feat(cli): add portable traces installer

[drewstone]

What changed

• Added a repo-level install.sh that installs @tangle-network/traces from npm, handles non-writable global prefixes by using ~/.local, and verifies the exact installed binary path before falling back to PATH.
• Added traces --version / traces version.
• Added pnpm check:package to prove the npm tarball ships dist/cli.js, SDK entrypoints, README, installer, and package metadata.
• Wired the package check into CI, the publish workflow, and prepublishOnly.

Why

Dotfiles and other repos should depend on the released traces CLI, not a local source checkout on one machine.

Verification

• pnpm typecheck
• pnpm test (13 files, 82 tests)
• pnpm build
• node dist/cli.js --version -> traces 0.8.11
• pnpm check:package -> package binary ok for @tangle-network/traces@0.8.11
• PATH=<fake-old-traces>:$PATH ./install.sh --prefix $(mktemp -d) -> validated the temp-prefix binary, not the fake PATH binary; installed bin/traces; --help returned 2804 bytes
• git merge-tree --write-tree origin/main HEAD -> 6626fc27afd06a18ac0b39b35fc31a6ee6d7c478

[tangletools]

✅ Auto-approved drewstone PR — b6074b1c

This PR was opened by the trusted drewstone account.
The full PR reviewer audit still runs separately and will publish findings if it detects issues.

_{tangletools · auto-approval · reason: drewstone_author · 2026-07-03T04:20:24Z}