* fix(extract): force UTF-8 encoding on subprocess + loud failure on chunk errors
On Windows cp1252, subprocess.run(..., text=True) without encoding= raises
UnicodeEncodeError for chars like → ✅ ≥ in chunk content. Both
_call_claude_cli (llm.py:426) and the _call_llm claude-cli branch (llm.py:959)
lacked encoding=.
- Add encoding="utf-8" to both subprocess.run sites.
- Track failed_chunks in extract_corpus_parallel merged result dict.
- Print [graphify] WARNING: N/M semantic chunk(s) failed summary to stderr at
end of run when any chunk failed, so silent partial failures are visible.
- Add tests/test_charmap_encoding.py: 10 regression tests covering subprocess
encoding kwarg, loud-failure summary, and substitution validation.
Closes#3
* style: drop fork-local issue refs from llm/test comments
Christopher Beaulieu