docs: add release process to AGENTS.md and CONTRIBUTING.md

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

Author: ewels

AGENTS.md

@@ -221,6 +221,24 @@ GitHub Actions (`.github/workflows/ci.yml`) runs on push to `main` and all PRs:
 
 All three must pass. Uses `dtolnay/rust-toolchain@stable` and `Swatinem/rust-cache@v2`.
 
+## Release Process
+
+Releases are triggered via **workflow dispatch** (GitHub Actions UI or `gh workflow run release`).
+The workflow (`.github/workflows/release.yml`) does the following:
+
+1. Reads the version from `Cargo.toml` and validates it matches `Cargo.lock`.
+2. Builds all binary variants (8 targets) and Docker images (baseline + 3 SIMD).
+3. Only after all builds pass: creates a git tag, GitHub release (with changelog from `CHANGELOG.md`), and uploads binary artifacts.
+4. Publishes to crates.io as the final step.
+
+To prepare a release:
+
+1. Update `version` in `Cargo.toml`.
+2. Run `cargo update --package rustqc` to sync `Cargo.lock`.
+3. Add a new section to `CHANGELOG.md` following the existing format.
+4. Commit and push to `main`.
+5. Trigger the Release workflow via GitHub Actions.
+
 ## Key Dependencies
 
 | Crate                  | Purpose                               |

CONTRIBUTING.md

@@ -172,6 +172,20 @@ All pull requests must pass three checks:
 2. `cargo fmt --check`
 3. `cargo clippy -- -D warnings`
 
+## Releasing
+
+Releases are triggered via **workflow dispatch** (GitHub Actions UI or `gh workflow run release`).
+The workflow builds all binary variants and Docker images, and only creates the tag, GitHub release,
+and crates.io publish after all builds pass.
+
+To prepare a release:
+
+1. Update `version` in `Cargo.toml`.
+2. Run `cargo update --package rustqc` to sync `Cargo.lock`.
+3. Add a new section to `CHANGELOG.md` following the existing format.
+4. Commit and push to `main`.
+5. Trigger the **Release** workflow via GitHub Actions.
+
 ## Reporting issues
 
 Please open a [GitHub issue](https://github.com/seqeralabs/RustQC/issues) with: