[codex] Convert client signals to monorepo

[dangra]

Summary

Convert client-signals from a Go-only repository into a shared-contract monorepo with language packages for Go, JavaScript, Python, and Elixir.

What changed

• Moved the Go module into go/ and updated its module path to github.com/superfly/client-signals/go.
• Added shared contract fixtures under spec/ for markers, sanitization, parent classification, headers, and User-Agent suffixes.
• Added library-only implementations for JavaScript, Python, and Elixir.
• Added package-specific README.md and AGENTS.md files, keeping root docs language-neutral.
• Updated shared docs and GitHub Actions checks for the monorepo layout.

Impact

This intentionally changes the Go import path. Existing Go consumers must update from github.com/superfly/client-signals to github.com/superfly/client-signals/go.

Package publishing for npm, PyPI, and Hex is documented but not automated in this PR.

Validation

• (cd go && go test ./...)
• (cd javascript && npm test)
• (cd python && python3 -m unittest)
• (cd elixir && mix test)
• (cd go && GOOS=linux GOARCH=amd64 go build ./...)
• (cd go && GOOS=darwin GOARCH=arm64 go build ./...)
• (cd go && GOOS=windows GOARCH=amd64 go build ./...)

[Copilot]

Pull request overview

Convert client-signals into a shared-contract monorepo, with spec/ fixtures defining cross-language behavior and new library implementations for Go, JavaScript, Python, and Elixir (with Go moved under go/ and a new import path).

Changes:

• Introduced spec/ JSON fixtures for markers, sanitization, parent classification, and header/User-Agent behavior, and updated docs to describe the shared contract.
• Added new JavaScript, Python, and Elixir library implementations plus fixture-driven test suites to keep behavior aligned.
• Moved the Go module into go/, updated its module path, and updated CI to run per-language test jobs in the monorepo layout.

Reviewed changes

Copilot reviewed 34 out of 53 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
spec/sanitize-fixtures.json	Adds shared sanitization fixtures for self-declared agent values.
spec/README.md	Documents the purpose and intended usage of shared spec fixtures.
spec/parent-fixtures.json	Adds shared fixtures for parent process name bucketing.
spec/markers.json	Defines the shared known agent-marker table used across languages.
spec/header-fixtures.json	Adds shared fixtures for emitted headers and UA suffix behavior.
README.md	Updates root documentation for monorepo layout and shared contract.
python/test_client_signals.py	Adds Python unittest coverage, including fixture alignment checks.
python/README.md	Documents Python package usage and API surface.
python/pyproject.toml	Adds Python package metadata for the monorepo layout.
python/client_signals/core.py	Implements Python detection + header/UA helpers per shared contract.
python/client_signals/init.py	Exposes the Python public API surface.
python/AGENTS.md	Adds Python package agent/dev constraints and commands.
javascript/test/index.test.js	Adds Node test coverage, including shared fixture checks.
javascript/src/index.js	Implements JavaScript detection + header/UA helpers per shared contract.
javascript/README.md	Documents JavaScript package usage and API surface.
javascript/package.json	Adds JavaScript package metadata and test script.
javascript/AGENTS.md	Adds JavaScript package agent/dev constraints and commands.
go/transport.go	Adds Go header helpers and RoundTripper wrapper for attaching signals.
go/transport_test.go	Adds Go tests for transport/header/UA behavior.
go/spec_contract_test.go	Adds Go fixture-driven contract tests against spec/.
go/signals.go	Adds Go Signals, Detect, and DetectOnce implementation under go/.
go/signals_test.go	Adds Go tests for signal composition and caching behavior.
go/README.md	Documents Go module import path change and updated API usage.
go/parent.go	Adds Go parent process classification helpers.
go/parent_windows.go	Adds Windows parent process lookup via Toolhelp32 snapshot.
go/parent_test.go	Adds Go tests for parent classification and smoke-test lookup.
go/parent_other.go	Adds fallback parent lookup behavior for unsupported platforms.
go/parent_linux.go	Adds Linux parent process lookup via /proc/<ppid>/comm.
go/parent_darwin.go	Adds macOS parent process lookup via sysctl.
go/markers.go	Adds Go mirror of the shared known marker table.
go/interactive.go	Adds Go stdout “interactive” detection helper.
go/interactive_test.go	Adds Go test for interactive detection behavior.
go/go.sum	Adds Go dependency sums (x/sys).
go/go.mod	Moves Go module path under go/.
go/cmd/main.go	Updates CLI to import the new Go module path.
go/ci.go	Adds Go CI detection helper.
go/ci_test.go	Adds Go tests for CI detection semantics.
go/AGENTS.md	Adds Go package agent/dev constraints and commands.
go/agent.go	Adds Go agent detection + invoked-by sanitization.
go/agent_test.go	Adds Go tests for agent detection precedence and sanitization.
go/.golangci.yml	Updates Go lint config for the new module path.
elixir/test/test_helper.exs	Adds ExUnit bootstrap for Elixir tests.
elixir/test/client_signals_test.exs	Adds Elixir tests, including shared fixture checks.
elixir/README.md	Documents Elixir package usage and API surface.
elixir/mix.exs	Adds Elixir project/package metadata.
elixir/lib/client_signals.ex	Implements Elixir detection + header/UA helpers per shared contract.
elixir/AGENTS.md	Adds Elixir package agent/dev constraints and commands.
elixir/.formatter.exs	Adds Elixir formatter configuration.
docs/signals.md	Updates shared signal rationale docs for multi-language context.
docs/markers.md	Updates marker rationale docs to reference shared spec/ source of truth.
AGENTS.md	Updates repository-wide agent guidance for monorepo structure.
.gitignore	Ignores language-specific build/test artifacts (node/python/elixir).
.github/workflows/checks.yml	Updates CI workflow for monorepo layout and per-language test jobs.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.