readViaStream (used for files ≥8 MB) reconstructs the full file as a
single string via chunks.join('\n'), giving the same peak allocation as
readFile. Callers then call content.split('\n'), creating a second copy.
With FILE_READ_CONCURRENCY=16 and files up to 128 MB this can exhaust
the V8 heap (~6 GB theoretical peak).
readSessionLines already exists as a proper async generator that yields
one line at a time. Switch both hot-path callers to iterate it directly
so the full file string is never held in memory.
Adds two tests: a spy test confirming readSessionLines is called (not
readSessionFile), and a 500-entry correctness test.
Fixes#131
Claude Code does not document or implement a .claudeignore feature.
The junk-reads detector's fix is now a CLAUDE.md instruction asking
Claude to avoid generated/dependency directories. The separate
detectMissingClaudeignore finding and its tests are removed; checking
for the presence of a non-existent file has no signal.
Closes#61.
