cx-string-append-unreserved — removed 2026-10-23 (Asia/Shanghai)

这篇还没有中文，下面是英文原文。

Status: removed. The recorded -O2 before/after for char append is about 1.09×. Retained capacity was about 1.23× (char) and 1.31× (64-byte chunks). No scoped win at or above about 2× in the JSONL. No matcher.

• Slug never reused.
• Historical JSONL, memory probe, and the note stay beside this file. Fixtures are under _removed/fixtures/.