When FOR body contains APPEND+REPLACE and no USE/SELECT:
- Hoist WorkAreaManager, Current(), *dbf.DBFArea outside loop
- Pre-compute FieldIndex for all REPLACE fields once
- REPLACE inside loop uses cached _rdbf and _rfiN variables
- APPEND inside loop uses cached _rarea (no WA lookup per iter)
Safety: collectReplaceFields returns nil if USE/SELECT found in body
(workarea may change → cannot safely cache). Falls back to normal emit.
10K APPEND benchmark: 28ms (Harbour 27ms — essentially equal!)
82/82 stress test PASS. 14 packages ALL PASS.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Charles KWON OhJun
bb6cf7c612