Task

Create or update GitHub Actions workflows in .github/workflows/.

Detection Phase

First, detect the project ecosystem by inspecting the repo root:

Language & package manager: Check for mix.exs, package.json, Cargo.toml, go.mod, pubspec.yaml, pyproject.toml, Makefile, flake.nix, etc.
Project type: Determine if this is a library/package or an application — this affects whether release.yml publishes to a registry.
Existing workflows: Read any existing .github/workflows/*.yml to preserve custom jobs or secrets already configured.
Test framework: Detect test runner from config (ExUnit, Jest/Vitest, cargo test, go test, flutter_test, pytest, etc.)
Build tool: Detect build commands (mix compile, npm run build, cargo build, go build, flutter build, etc.)
Linter/formatter: Detect available checks (mix format --check-formatted, mix credo, eslint, clippy, go vet, dart analyze, ruff, etc.)

Generate only the workflows that apply. Use the detected ecosystem to fill in concrete commands — never use placeholder commands.