feat: add E2E smoke test script and CI/CD pipeline plan

- Create scripts/smoke-test.sh for live server verification (7 checks)
- Document planned GitHub Actions CI/CD pipeline in docs/ci-cd-plan.md
- Integration tests deferred to future task (require test harness setup)

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

docs/ci-cd-plan.md

@@ -0,0 +1,37 @@
+# CI/CD Pipeline Plan
+
+## CI Workflow (on push to main + PRs)
+
+### Jobs
+1. **Rust checks**
+   - `cargo clippy --all-targets --all-features` (zero warnings)
+   - `cargo fmt --all -- --check`
+   - `cargo test --all-features`
+
+2. **Frontend checks**
+   - `npm run type-check` (vue-tsc)
+   - `npm run lint` (eslint)
+   - `npm test` (vitest)
+
+3. **Script validation**
+   - `bash -n` on all .sh files
+   - `shellcheck` on critical scripts
+
+### Merge policy
+All checks must pass before merge.
+
+## Release Workflow (on tag push v*)
+
+### Jobs
+1. Build Linux binary (cross-compile x86_64 + ARM64)
+2. Build frontend (`npm run build`)
+3. ISO build via SSH to build server
+4. QEMU smoke test of ISO
+
+## Pre-requisites
+- GitHub Actions runners with Rust toolchain
+- SSH key for build server access
+- Branch protection on main
+- Image digest manifest from `scripts/image-versions.sh`
+
+## Estimated implementation: 2 weeks