Three independent improvements to extract_corpus_parallel:
1. Token-aware chunking. Replaces `chunk_size=20` static packing with
a greedy packer keyed on `token_budget` (default 60_000), grouped
by parent directory so related artefacts share a chunk. Pass
`token_budget=None` to fall back to fixed-count packing.
2. Optional tiktoken (added to the [kimi] extra). When available,
`_estimate_file_tokens` uses cl100k_base for accurate counts;
without it, the existing chars/4 heuristic kicks in. Kimi-K2 ships
a tiktoken-based tokenizer so estimates against Moonshot are very
close to truth.
3. True parallelism. The function name said "parallel" but the body
was a sequential for-loop. Now uses ThreadPoolExecutor capped at
`max_concurrency` (default 4 — conservative against provider rate
limits). `on_chunk_done(idx, total, result)` still fires once per
chunk with the original submission idx so progress UIs work
unchanged. `max_concurrency=1` skips the pool to preserve
sequential semantics.
Plus failure tolerance: a chunk raising is now caught, logged to
stderr, and the run continues. Other chunks' results merge as normal.
On a 162-file repo (~125k words), the same work that took ~36 min
sequential under the old code finishes in ~7 min.
Jason Matthew
cc5c54574d