Prepare stable v0.1.12 release

[Herbertmt978]

Summary

• Promote the tested v0.1.12-beta behavior to stable v0.1.12.
• Update the add-on, Compose, documentation, changelog, and curated release notes while keeping the Home Assistant add-on stage experimental.
• Harden the protected manual workflow so stable releases become Latest, prereleases cannot become Latest, all release dispatches are serialized, and release identity, immutability, and exact notes are verified.
• Extend release validation and regression coverage for the stable/prerelease paths.
• Make no Grott runtime, layout, Dockerfile, dependency, entrypoint, or sensor-profile default changes relative to immutable v0.1.12-beta.

Verification

• 540 passed
• Release and Home Assistant add-on validators passed on the clean candidate.
• Ruff checks, compileall, pip check, and the hash-locked dependency audit passed with no known vulnerabilities.
• Exact-commit runtime and add-on images passed read-only, no-network, capability-dropped final-container validation.
• The exact-commit application manifests match the published beta after line-ending normalization: zero differences across 17 runtime files and 18 add-on files.
• The inherited beta UAT covered both MOD inverters, restart recovery, retained discovery [32, 32], zero runtime errors, current ShinePhone values, and a verified Home Assistant backup.
• The owner explicitly waived only the remaining observation period; hosted CI, protected merge, exact-merge-SHA master CI, tag, environment, image, and publication gates remain required.

Compatibility boundary

Live hardware evidence covers the two available MOD inverters. SPH, MIN, TL3, T060120, and generic preservation is covered by deterministic fixtures and final-container checks, not live hardware. Stable describes the release channel, not universal hardware qualification.

Release and rollback boundary

This PR does not create a tag, publish an image, or create a release. After merge and successful CI at the exact master merge SHA, publication still requires the protected annotated v0.1.12 tag and a manual release-workflow dispatch. The resulting release must be immutable, non-prerelease, and repository Latest; v0.1.12-beta remains the historical prerelease.

Rollback remains pinned to:

• Runtime: ghcr.io/herbertmt978/grott@sha256:066d806774a147bc4c448761d026eb831cdcfa29bc32ef3a1c361a36a2ea361a
• Add-on: ghcr.io/herbertmt978/grott-ha-docker@sha256:410f2b2e4dfe810aa1d9d8b8591eaae0852ae9f61486d78f663cd6a95c2ab6f1

Home Assistant rollback also requires the verified full backup and retained MQTT recovery evidence; changing only the image cannot restore registry or broker state.

Permission and use boundary

The fork owner asserts that redistribution permission has been obtained. This does not authorize commercial use or reuse unless Johan Meijer separately agrees, and any financial reward or appreciation must be directed to him.