Hooked Class Deprecation

[jlarson4]

Description

This is the preparation for the removal of Hooked* classes

• Removed the five model classes — HookedTransformer, HookedEncoder, HookedEncoderDecoder, HookedAudioEncoder, BertNextSentencePrediction.
• Removed the supporting stack — loading_from_pretrained.py, config/hooked_transformer_config.py, the whole components/ tree (26 files) and pretrained/weight_conversions/ (33 files), factories/mlp_factory.py, the train.py / utils.py shims, and the two HT-dependent capture scripts.
• Kept-side repairs — __init__.py reshaped (lazy-legacy map + de-shadowing removed, __all__ trimmed); config / multi_gpu / key_value_cache retyped off the deleted config; remote_bridge switched to utilities; get_official_model_name rehomed to supported_models.py; goldens pure-helpers rehomed to goldens_capture_spec.py; make_docs.py HT-table generator removed.
• Tests — deleted ~30 HT-only test files; re-anchored the post-norm, MoE-expert-fold, and resolver guards onto the surviving code; added test_bert_weight_surface.py; made the doctest guard permanent.
• Config / docs / CI — dead Hooked* filterwarnings, apidoc excludes, and QUARANTINES rows removed; the HookedTransformer model-properties table preserved as a committed static page with a 4.0 deprecation banner.
• Notebook hard breaks — Main_Demo (checkpoint-labels import), Colab_Compatibility (loading → supported_models), LIT (call site → bridge), hf-tl-logit-comparator (ported to bridge); stale HT-deprecation stderr stripped from Grokking / No_Position outputs.
• Public-API tombstones — _REMOVED_IN_4_0 directed-message map in __init__.py's __getattr__.
• Code fixes — case-insensitive get_official_model_name restored (+ regression test); hook_points import-shim removed as promised (directed error); alias-warning over-promise softened.
• Contributor guidance — AGENTS.md mirror rule + §2 table + paragraph, .github/copilot-instructions.md, config/AGENTS.md de-HT'd.
• Package READMEs — lit/README.md (+ dead __all__ entry), benchmarks/README.md (use_ht_reference → use_hf_reference, dead link); README PyPI blurb; contributing.md banner.
• Bookkeeping — doc_sanitize.cfg dead sanitizer + duplicate section; goldens provenance + 3 dead capture-script comments; QUARANTINES T5 note.
• Coverage — new test_head_detector_bridge.py and test_model_protocol_bridge.py.
• Packaging — better-abc + muutils dropped from pyproject.toml; uv.lock refreshed.

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have not rewritten tests relating to key interfaces which would affect backward compatibility