The callback/observer synthesizers loaded every function and method node into
memory at once (getNodesByKind('function'/'method')) before scanning them down
to a tiny matched subset. On a symbol-dense project that array is gigabytes, so
indexing spiked the JS heap and aborted with "JavaScript heap out of memory".
Add QueryBuilder.iterateNodesByKind (a lazy node:sqlite cursor) and stream the
synthesizer scans instead of materializing them. Parsing and reference
resolution were already bounded; only the synthesis enumeration wasn't.
Measured on 80 files x 14k functions (~1.1M nodes): peak RSS 3717 MB -> 1318 MB,
no OOM. Full suite green; synthesized edges unchanged.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
