CI: run vendored template suites against the SDK checkout

[jdchawla29]

Stacked on #512.

Adds a templates CI job: for each of environments/{coding,cua}, uv sync the template's pinned dependencies, install the SDK from the checkout over the hud pin (editable), then run the template's own ruff format --check, ruff check, and pytest.

This makes template breakage an SDK PR failure rather than something discovered after release. The coding template's suite includes a full local rollout (serve → connect → run → grade, golden=1.0/baseline=0.0), so the v6 serving contract is exercised end to end on every PR. Docker-dependent tests self-skip; those move to the nightly/release-gate job in a follow-up.

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Note

Low Risk
CI-only change with no runtime or SDK behavior modifications; risk is limited to longer CI runs or flaky template tests blocking merges.

Overview
Adds a templates CI job that runs on every PR alongside the existing SDK test matrix.

For each vendored template (environments/coding and environments/cua), the job syncs the template’s pinned deps, replaces the published hud pin with an editable install of the repo root (uv pip install -e ../..), then runs that template’s ruff format (check), ruff check, and pytest.

This turns template breakage into an SDK PR failure instead of a post-release discovery. The coding template’s pytest suite includes hermetic local rollout coverage (serve → connect → run → grade), so the v6 serving contract is exercised end-to-end on every PR; Docker-only integration tests are expected to skip in this job.

^{Reviewed by Cursor Bugbot for commit 5b253c2. Bugbot is set up for automated code reviews on this repo. Configure here.}

HUD-2276

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Enforce the checked-in template locks

For both matrix entries, if a PR changes environments/<template>/pyproject.toml without updating its uv.lock, this command silently regenerates the lock in the runner and tests that uncommitted state, allowing CI to pass while the checked-in reproducible environment remains stale. uv sync --help documents --locked as “Assert that the uv.lock will remain unchanged”; use that option here so dependency and lock changes must be committed together.

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[chatgpt-codex-connector]

Resolve the checkout in a clean template dependency graph

When the checkout removes a dependency previously supplied by the released hud package, the preceding sync installs that old dependency from the template lock and this additive editable install leaves it behind. Template tests can therefore keep importing an undeclared dependency and pass even though a clean installation against the checkout would fail; uv pip install --help confirms that removing extraneous packages requires --exact. Resolve hud from ../.. as part of the template environment rather than layering it over the released package's dependency set.

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