Add CI: Rust and Python test workflows

[AjayThorve]

Adds two GitHub Actions workflows so the existing test suite runs on PRs:

• ci_rust.yml — cargo fmt --check, cargo check -p fabric-python, and cargo test --workspace (which includes the schema-snapshot checks that guard the public contract).
• ci_python.yml — builds the native extension, then runs the dependency-free smokes (smoke_cli, smoke_sdk, smoke_native_sdk, smoke_hermes_cli, smoke_hermes_config_mapping, smoke_swebench_style, smoke_local_env_e2e, smoke_environment_handle).

Why

The repo had a test suite but nothing ran it on PRs, so contract/schema drift could merge unnoticed. Both workflows are single-platform (ubuntu-latest), need no secrets, and mirror nemo-relay's Rust/Python split and pinned action SHAs.

Triggers

pull_request + push to main. No secrets are required, so the checks report directly on the PR (unlike the docs workflow, which uses copy-pr-bot mirror branches for FERN_TOKEN).

Excluded

• Gated integration smokes (smoke_hermes_sdk, smoke_relay_integration, smoke_harbor_*) — they need NVIDIA_API_KEY / a running Hermes / a sibling harbor checkout.
• smoke_sdk_concurrency — currently flaky (two concurrent runs can collide on runtime_id); excluded until that is fixed.

Verified locally

All included checks pass (cargo fmt/check/test --workspace green; all 8 smokes pass).

Resolves FABRIC-32

Summary by CodeRabbit

• Chores
  • Updated continuous integration workflows to enforce automated code quality checks and comprehensive testing across Python and Rust components.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 47001ba7-dbc8-46ff-a1d8-355c18b0b95c

📥 Commits

Reviewing files that changed from the base of the PR and between dfb73c3 and ea07130.

📒 Files selected for processing (2)

• .github/workflows/ci_python.yml
• .github/workflows/ci_rust.yml

🚧 Files skipped from review as they are similar to previous changes (2)

• .github/workflows/ci_python.yml
• .github/workflows/ci_rust.yml

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📝 Walkthrough

Walkthrough

Two GitHub Actions workflows are added: ci_rust.yml runs cargo fmt, cargo check, and cargo test on the Rust workspace; ci_python.yml builds the native extension via uv and executes a fixed list of Python smoke scripts. Both use per-ref concurrency with cancellation and read-only permissions.

Changes

CI Workflows

Layer / File(s)	Summary
Rust CI workflow .github/workflows/ci_rust.yml	Defines PR/push triggers, concurrency cancellation, stable Rust with rustfmt, shared Cargo cache (fabric-rust key), then runs format check, locked fabric-python build check, and locked workspace tests in a 30-minute ubuntu-latest job.
Python CI workflow .github/workflows/ci_python.yml	Defines same trigger/concurrency/permission pattern, installs Rust stable + uv, creates a Python 3.12 venv, installs the project in editable mode (building the native extension), installs pyyaml, and runs ordered smoke scripts with set -euo pipefail and ::group:: log markers.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Add CI: Rust and Python test workflows' directly and concisely summarizes the main change: adding two CI workflows for Rust and Python testing.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

_{Comment @coderabbitai help to get the list of available commands.}

[linear]

FABRIC-32 Repo docs/CI infra

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In @.github/workflows/ci_rust.yml:
- Line 32: The pinned SHAs for the GitHub workflow actions do not match their
stated version tags. For the actions/checkout action, update the pinned SHA from
the current value to df4cb1c069e1874edd31b4311f1884172cec0e10 which corresponds
to the v6 tag. For the Swatinem/rust-cache action, update the pinned SHA to
23869a5bd66c73db3c0ac40331f3206eb23791dc which corresponds to the v2.9.1 tag.
Alternatively, if these older commits are intentionally being used as
pre-release versions, remove the version comments to avoid confusion between the
pinned SHA and the claimed version.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: c90af9a9-dee3-4750-aa23-520d74795997

📥 Commits

Reviewing files that changed from the base of the PR and between 7c9b0c1 and 842cf46.

📒 Files selected for processing (2)

• .github/workflows/ci_python.yml
• .github/workflows/ci_rust.yml