feat: ESLint, shell completions, Docker, nfpm packaging, CI/CD

- ESLint with typescript-eslint + prettier (eslint.config.js)
- Shell completions for bash and fish (scripts/generate-completions.ts)
- Multi-stage Dockerfile for bastion (fedora:43 + dnsmasq + node)
- nfpm.yaml for RPM/DEB packaging with bun-compiled binary
- Build scripts: build-rpm.sh, build-bastion.sh, publish-rpm/deb.sh
- Gitea Actions CI/CD: lint, typecheck, test, build, publish

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bastion/nfpm.yaml

@@ -0,0 +1,20 @@
+name: lab
+arch: amd64
+version: 0.1.0
+release: "1"
+maintainer: michal
+description: Lab infrastructure CLI for bare-metal provisioning
+license: MIT
+contents:
+  - src: ./dist/lab
+    dst: /usr/bin/lab
+    file_info:
+      mode: 0755
+  - src: ./completions/lab.bash
+    dst: /usr/share/bash-completion/completions/lab
+    file_info:
+      mode: 0644
+  - src: ./completions/lab.fish
+    dst: /usr/share/fish/vendor_completions.d/lab.fish
+    file_info:
+      mode: 0644