Upstream merged MemPalace#682-684 (our splits), MemPalace#687 (dry-run None room),
MemPalace#695/MemPalace#708 (convo_miner full response), MemPalace#732 (0-chunk re-processing),
plus VitePress docs site. Conflicts:
- config.py: take upstream's [^\W_] regex (our MemPalace#683 merged version)
- miner.py: integrate upstream's early-return for tiny files, dedupe
  dry-run read path
- test_miner.py: keep our detect_room tests + upstream's dry-run test
- CONTRIBUTING.md: take upstream's org URL update

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Remove the ai_lines[:8] truncation in _chunk_by_exchange() so full AI
responses are stored. Add _register_empty_file() sentinel drawer for
conversation files that produce 0 chunks, preventing infinite
re-processing on subsequent runs.

Also fix pre-existing test_miner assertion that expected int from
process_file (now returns tuple since PR #45).

Ports upstream MemPalace#654, MemPalace#692, MemPalace#695.

Remove the ai_lines[:8] truncation in _chunk_by_exchange() so full AI
responses are stored. Add _register_empty_file() sentinel drawer for
conversation files that produce 0 chunks, preventing infinite
re-processing on subsequent runs.

Also fix pre-existing test_miner assertion that expected int from
process_file (now returns tuple since PR #45).

Ports upstream MemPalace#654, MemPalace#692, MemPalace#695.

… 0-chunk files

Three upstream fixes ported together because they're conceptually one
"convo_miner polish" pass on the same exchange-chunking path.

1. Remove ai_lines[:8] truncation (upstream d52d6c9, PR MemPalace#695). The
   _chunk_by_exchange path was silently dropping every line past line 8
   of the AI response, violating the verbatim-storage principle.

2. Split oversize exchanges across drawers (upstream 9b60c6e, PR MemPalace#708).
   Now that the full response is preserved, an exchange that exceeds
   CHUNK_SIZE (800 chars, aligned with miner.py) is split into
   consecutive drawers instead of a single oversized one. Adds
   CHUNK_SIZE module constant.

3. Register a no-embedding sentinel for files that produce zero chunks
   (upstream 87e8baf, PR MemPalace#732). mine_convos has three early-exit paths
   (OSError, content too short, zero chunks) that previously wrote
   nothing — file_already_mined() then returned False on the next run
   and the file was re-read every time.

Adapted MemPalace#3 for the PG backend: the upstream sentinel uses
collection.upsert() (ChromaDB API). This fork instead adds a
PalaceDB.register_empty_file() method that inserts a row directly with
embedding=NULL and metadata.ingest_mode='registry', so the sentinel is
free of embedding cost and invisible to vector search. file_already_mined()
already keys on source_file + source_mtime, so the existing path picks
up the sentinel without further changes.

Three behavioural tests added: full AI response preserved, oversize
exchange split across drawers, and the sentinel + file_already_mined
round trip.

Upstream:
  MemPalace@d52d6c9
  MemPalace@9b60c6e
  MemPalace@87e8baf

Co-authored-by: shafdev <[email protected]>
Co-authored-by: Sanjay Ramadugu <[email protected]>
Co-authored-by: Mikhail Valentsev <[email protected]>
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>