docs(blog): add v1.6.0 release announcement

Comprehensive release post covering Rust ecosystem, Terragrunt,
make fix, pre-push hooks, make release, tool version manifests,
git-cliff, and conventional commit scope updates.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: matthew-on-git

content/blog/2026-03-09-v160-release.md

@@ -0,0 +1,57 @@
+---
+title: "v1.6.0 Release"
+date: 2026-03-09
+description: "Rust, Terragrunt, make fix, pre-push hooks, make release, tool version manifests, and git-cliff -- the biggest dev-toolchain release yet."
+---
+
+v1.6.0 is the largest dev-toolchain release since launch. It adds the eighth language ecosystem, a companion infrastructure tool, three new Makefile targets, and several workflow improvements. This post summarizes everything that shipped.
+
+## Language and Tool Additions
+
+**Rust** is the eighth language ecosystem. The container ships clippy, rustfmt, cargo-audit, cargo-deny, and cargo test. The full toolchain is COPY'd from the official `rust:1-slim-bookworm` image, and security tools are installed via cargo-binstall. See the [Rust support announcement](/blog/2026-03-04-rust-support/) for details.
+
+**Terragrunt** ships as a companion tool to Terraform. Projects that use `terragrunt.hcl` files get automatic format checking with zero additional configuration. See the [Terragrunt announcement](/blog/2026-03-05-terragrunt-support/) for how detection and gating work.
+
+## New Makefile Targets
+
+**`make fix`** runs formatters and auto-fixable linter rules in-place across all eight language ecosystems. The intended workflow: run `make fix` to auto-remediate, then `make check` to verify. See the [`make fix` announcement](/blog/2026-03-03-make-fix-and-mirror-automation/) for the full story.
+
+**`make release VERSION=x.y.z`** automates the release process. It validates the version format, ensures the working tree is clean, creates a signed git tag, and pushes it to trigger the build pipeline. The tag push fires the existing GitHub Actions workflow that builds, signs, and publishes the container image.
+
+```console
+$ make release VERSION=1.6.0
+Validating version format...
+Creating tag v1.6.0...
+Pushing tag to origin...
+Tag v1.6.0 pushed — build pipeline triggered.
+```
+
+**Pre-push hooks** run `make check` before every `git push`, catching issues before they reach CI. The hook is installed via `make install-hooks` and executes the full validation suite inside the container. If any check fails, the push is rejected with clear output about what needs fixing.
+
+## Workflow Improvements
+
+**Tool version manifests** are now attached to every GitHub release. The `report-tool-versions.sh` script runs inside the published container image and produces a JSON manifest listing every tool and its exact version across all eight language ecosystems. The [container versions page](/docs/container/versions/) is automatically updated from these release assets.
+
+**git-cliff** ships in the container for automated changelog generation. Projects that use conventional commits can generate changelogs with `git-cliff --output CHANGELOG.md` inside the container.
+
+**Conventional commit scopes** were expanded in v1.1.0 of the [pre-commit hook](https://github.com/devrail-dev/pre-commit-conventional-commits). The valid scope set grew from 8 to 15, adding `ruby`, `go`, `javascript`, `rust`, `security`, `changelog`, and `release`. All DevRail repositories were bumped to v1.1.0.
+
+## Upgrade
+
+Pull the latest image:
+
+```console
+docker pull ghcr.io/devrail-dev/dev-toolchain:v1
+```
+
+Or pin to the exact version:
+
+```console
+docker pull ghcr.io/devrail-dev/dev-toolchain:1.6.0
+```
+
+Projects using the DevRail template Makefile with `:v1` already get the latest release on next `make check`. To pin an exact version, set `DEVRAIL_TAG` in your Makefile.
+
+## Full Changelog
+
+See the [CHANGELOG](https://github.com/devrail-dev/dev-toolchain/blob/main/CHANGELOG.md) for the complete list of additions, changes, and fixes in v1.6.0.