Summary

Reimplements the AttributeError member-name suggestions (added in #124, v2.0.55) on top of a ClassObject.tp_getattro override, and removes the miss-only __getattr__ hook. Behavior is unchanged — a missing attribute on a .NET object still gets a snake_case Did you mean ...? hint:

>>> System.String("x").lenght
AttributeError: 'String' object has no attribute 'lenght' Did you mean: 'length'?

Version bumped to 2.0.56.

Why replace the hook

#124 installed a shared __getattr__ on every reflected type and manually rewired tp_getattro to CPython's private slot_tp_getattr_hook (address scraped from a probe class). That is a lot of low-level CPython surgery on the type system, done for one reason: to keep the successful attribute-access ("hit") path free of the small per-access cost that a tp_getattro override adds.

Benchmarking showed that cost is not worth the complexity:

• The per-access overhead of the tp_getattro override is ~17–19 ns/access.
• On realistic Lean backtests and a 50-algorithm regression subset it was within run-to-run noise (< 0.1% aggregate) — only a pathological loop dominated by raw C# property reads (~117M accesses) showed a measurable ~9%.

Given the negligible real-world impact, this PR drops the slot manipulation entirely and keeps the enrichment in a straightforward tp_getattro that delegates to PyObject_GenericGetAttr and only does work on a miss.

Diff vs master

 src/runtime/AttributeErrorHint.cs | 109 ------  (removed: hook + manual slot wiring)
 src/runtime/PythonEngine.cs       |   7 ---     (no Initialize/Shutdown hook calls)
 src/runtime/TypeManager.cs        |   4 --      (no per-type install)
 src/runtime/Types/ClassBase.cs    |  73 +--      (inline suggestion building)
 src/runtime/Types/ClassObject.cs  |  15 ++       (tp_getattro override)

DynamicClassObject continues to enrich on its own attribute-miss path (unchanged). Suggestions are ranked by case-insensitive Levenshtein distance + substring containment, dunder names are skipped, and member names are emitted in snake_case (const/static-readonly → UPPER_CASE) via the existing ToSnakeCase helpers.

Testing

• Python tests (tests/test_class.py) and embedding tests (src/embed_tests/TestPropertyAccess.cs) — unchanged from Suggest similar member names on AttributeError for .NET objects #124 and passing.
• Full Lean QuantConnect.Tests Python/Pandas unit suite and all Python/* regression algorithms were previously run against this feature with zero regressions vs master (all failures pre-existing/environmental).

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