Major rewrite based on Harbour dbfntx1.c analysis:
NTX B-tree traversal (ntx.go):
- nextKey: rewritten to match hb_ntxTagNextKey exactly
- Advance iKey, check right child, descend via goLeftmost
- Walk up stack on page exhaustion, truncate stackLevel
- prevKey: rewritten to match hb_ntxTagPrevKey
- Check left child (only if iKey < keyCount), descend via goRightmost
- Walk up stack for BOF detection
- goRightmost: internal nodes get iKey=keyCount (rightmost child),
leaf nodes get iKey=keyCount-1 (last key) — matches Harbour
NTX B-tree build (build.go):
- CreateIndex: proper B-tree insertion (insert keys one by one)
- insertKeyBTree: search → insert at leaf → propagate splits up
- pageInsertKey: Harbour-style offset swapping (not data moving)
- pageSplit: collect all entries, split at midpoint, promote separator
- Proper offset table initialization for all pages
Unit tests: all 5 RDD packages PASS
Stress test: partial progress (Seek issues with split pages)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Charles KWON OhJun
d2c17c7898