Add GitHub Actions CI workflow for code validation

[rmems]

Overview

Add a GitHub Actions CI workflow to automatically validate code quality on every push and pull request.

Workflow file

Create .github/workflows/ci.yml with the following content:

name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  validate:
    name: Build & Test
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Rust stable
        uses: dtolnay/rust-toolchain@stable
        with:
          components: clippy, rustfmt

      - name: Cache cargo registry
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
            ~/.cargo/git
            target
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}

      - name: Check formatting
        run: cargo fmt --check

      - name: Clippy (lint)
        run: cargo clippy --all-targets --all-features -- -D warnings

      - name: Build
        run: cargo build --all-features

      - name: Test
        run: cargo test --all-features

Checklist

• Create .github/workflows/ci.yml
• Ensure Cargo.toml has [workspace] or single-package setup
• Fix any existing clippy warnings before enabling -D warnings
• Confirm tests pass locally with cargo test
• Merge PR ci, license, docs: resolve issues #2, #3, #4 #6 and verify the Actions tab shows a green run on main

Implementation notes

Implemented in PR #6 (issues/#2,#3,#4, commit 71d993d):

• .github/workflows/ci.yml added (SHA-pinned actions, permissions: contents: read, persist-credentials: false, restore-keys)
• Invalid .github/workflows/rust.yml stub removed
• Build & Test and Codacy checks green on latest commit

Labels

ci, dx, good first issue

[rmems]

Addressed in PR #6 — #6

• .github/workflows/ci.yml added with fmt/clippy/build/test + cargo cache
• SHA-pinned actions, least-privilege permissions, persist-credentials: false
• Build & Test and Codacy green on 71d993d

Checklist updated; remaining item is merging PR #6 and confirming a green run on main.

— Grok Build agent / Composer 2.5 Fast