v0.13.0

Added

• GitHub Action wrapper (uses: dgr237/tflens@vX.Y.Z). Composite action at the repo root packages tflens diff | whatif | statediff | validate with PR-comment plumbing so CI integration is a single uses: line. Inputs map 1:1 to the flags (command, path, ref, format, plan, state, args) plus PR-comment controls (comment-on-pr, comment-tag, pr-number, step-summary, fail-on-breaking). Outputs: output-file (path), exit-code (numeric), breaking (boolean string). Builds tflens from the action's own checkout via ${{ github.action_path }} so the binary version stays in lockstep with the action ref the consumer pinned (dgr237/tflens@v0.12.0 always runs tflens v0.12.0; no separate version input to drift). Sticky PR comment uses a hidden marker line (<!-- tflens-action:<tag> -->) so re-runs find + PATCH the existing comment instead of stacking new ones; body is JSON-encoded via jq --rawfile so backticks / $vars / quotes inside the markdown can't break the request shape. Default comment-tag is tflens — workflows that invoke the action twice (e.g. diff + statediff) should pass distinct tags so the comments don't overwrite each other. Step summary append ($GITHUB_STEP_SUMMARY) and PR commenting both skip silently when format != markdown. Documented in the new "GitHub Action" section of the README with a worked plan-enrichment example.