🐛 fix(tsl_syntax): repair lookup engine and reconcile reference facts

lookup.py: exempt code-anchored ASCII identifiers from the mixed
zh/en gate so exact hits are no longer dropped; dedup parent/child
sections in results; validate write-prelude anchors in --check.

references: correct interpreter-verified facts (case-as-expression,
control-flow semicolons, __line__/__stack_frame, tslObjects order,
destroy timing, ErrDefine, truncated outputs), fix headings, scope
qualifiers and reversed quotes; strip dead preamble metadata from all
24 pages.

packaging: exclude __pycache__/*.pyc from playbook and bundle copies;
update build test file-count assertion to match.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

skills/tsl-syntax-reference/references/19_namespace_libpath_and_unit_runtime.md

@@ -1,10 +1,5 @@
 # TSL 命名空间、Libpath 与 unit 运行时
 
-文档类型：语法深水专题
-是否可直接用于生成代码：仅部分
-是否含可直接照写示例：是
-是否含不可照写反例：是
-
 这一篇收拢 `unit` 的运行时行为，以及 `.tsf` / `namespace` / `libpath` 的查找规则。`unit` 的基础写法、`uses` 位置和重名解析，统一放在 [09_units_and_scope.md](09_units_and_scope.md)。
 
 ## 本篇职责