CI for deploy to devtest

[thesujai]

Summary

Closes #

Changes

How was this tested?

Checklist

• I have read the contributing guidelines
• pnpm build, pnpm test, pnpm typecheck, pnpm lint:ci, and pnpm format:check pass locally
• Tests added/updated where it makes sense
• No hand-edits to generated code (packages/trueforge-sdk, .github/fern/openapi/openapi.json, docs/openapi.json) — fork PRs omit SDK regen; maintainers regenerate after merge
• Docs / .env.example updated if configuration or behavior changed

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Note

Low Risk
CI-only change that writes pinned SHAs to a separate devtest deployment repo using existing GitHub App secrets; no runtime application or auth logic in trueforge itself.

Overview
Adds a GitHub Actions workflow that keeps the devtest deployment repo in sync with main in this repository.

On each push to main (or manual run), the job checks out truefoundry/trueforge-devtest-deployment, uses a GitHub App token, and updates trueforge.truefoundry.yaml and trueforge-controller.truefoundry.yaml so image.build_source.ref and image.build_source.branch_name point at the triggering commit and branch. It commits and pushes only when those pins change; concurrency is limited with deploy-devtest and in-progress runs are cancelled.

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[changeset-bot]

⚠️ No Changeset found

Latest commit: 88daabb

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

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[chiragjn]

Approving with comments