Release 1.0.0: TypeScript, CI, interface picker, --path & --host

[botre]

Summary

Modernizes the toolchain and ships v1.0.0. Single PR per agreed strategy — solo repo, coherent release story.

Toolchain

• Migrate to TypeScript + tsup (source moves to src/cli.ts, built to dist/cli.js with the shebang preserved). Lint via tsc --noEmit.
• Upgrade yargs 17 → 18, prettier 2 → 3, husky 7 → 9. Drop unused pretty-quick dev dep.
• Add Node engines: ^20.19.0 || ^22.12.0 || >=23 (yargs 18 requirement).

CI

• .github/workflows/check.yml — runs on PRs and via workflow_call (Node 22.x, lint + build).
• .github/workflows/release.yml — runs on push to master (Node 24.x, build, version bump via phips28/gh-action-bump-version, publish to npm with provenance via trusted publishing — id-token: write, no NPM_TOKEN needed).
• Mirrored from formspark/use-formspark.

CLI fixes

• Replace dns.lookup(os.hostname()) (returns loopback on Debian/Ubuntu, .local on macOS) with iteration over os.networkInterfaces().
• When multiple non-internal IPv4 interfaces are detected, classify them (wifi / ethernet / vpn / virtual / other), sort by priority, and prompt with a numbered list (Enter accepts default).
• Validate --port is an integer in [1, 65535].
• Wire up the -P short alias (was referenced but never bound).
• Drop dead async keywords.

New flags

• --path — append a route, e.g. --path /admin.
• --host — override the auto-detected LAN IP (Docker, multi-NIC, demos).

Docs / assets

• Rewrite README with an Options table and Examples section.
• Replace static screenshot with a vhs-generated demo gif (static/demo.tape checked in for regeneration; --host 192.168.1.42 keeps real IPs out of the recording).

Versioning

Version is 1.0.0-rc.0 in this branch. The release workflow's autobumper does a patch bump on merge, which (per semver) drops the prerelease tag and lands at 1.0.0.

⚠️ Avoid feat: / BREAKING keywords on the merge commit message — those would trigger minor/major bumps. The merge commit defaults to a patch bump, which is what we want.

Pre-merge prerequisite

Before merging, configure npm Trusted Publishing on npmjs.com for localview:

• npmjs.com → package settings → Trusted Publishing → add publisher
• Repo: formspark/localview, workflow: release.yml

Without this, the publish step in release.yml will fail (no token, no trusted publisher).

Test plan

• npm run lint clean
• npm run build produces dist/cli.js ~6 KB with shebang preserved
• node dist/cli.js --port 8080 renders QR with correct LAN IP
• -P 9090 short flag works
• --port abc / --port 99999 / no port → exit 1 with usage hint
• --path /admin and --path admin both produce /admin in URL
• --host 192.168.1.42 skips picker entirely
• Multi-interface picker on a 4-interface machine sorts wifi → vpn → docker correctly
• Trusted publishing configured on npmjs.com (see prerequisite above)
• Merge to master and confirm release workflow lands 1.0.0 on npm