ABC tickets: core library primitives

Discrepancies in abc/ — the foundational slice/buffer/net/poll/curl layer every other module builds on. Each entry is one ticket with its live state; it drops off once the ticket closes. The fix-and-land method is Issues. Memory-safety findings live under MEM; this topic is for behavioural/correctness gaps.

Active tickets

ABC-003 (UTF8_LEN[byte>>4] byte-length table shifted; multibyte lead bytes over-count) landed into the abc sub — 02a23dc3 (?/abc/.dogs) + pin cb71e65b. (BRO-004's incoherence was a separate bro bug, not this table — see ABC-003.)