fix(miner): harden Windows mine against ONNX bad_alloc + silent partial exits

Three small changes that together address the failure modes in #1296:

1. Add pnpm-lock.yaml and yarn.lock to SKIP_FILENAMES, mirroring the
   existing package-lock.json rule. A 24K-line pnpm-lock.yaml produced
   ~1124 chunks in one batch and tripped onnxruntime bad_alloc on
   Windows; pnpm/yarn lockfiles are no more useful to mine than npm's.

2. Skip any file that produces more than MAX_CHUNKS_PER_FILE (500)
   chunks, with a clear log line. Catches the broader class — generated
   CSV/JSON, build artifacts, etc. — that the named-file SKIP list will
   never fully cover. The cap is conservative (500 chunks * 800 chars ≈
   400 KB of source) so legitimate hand-written content still mines.

3. Print a partial-progress summary on any exception in _mine_impl, not
   just KeyboardInterrupt, then re-raise. Without this, an arbitrary
   exception (ONNX bad_alloc, chromadb HNSW error, OS fault) propagates
   silently — the operator sees only the last progress line and assumes
   the mine succeeded. The new path mirrors the KeyboardInterrupt
   summary (files_processed, drawers_filed, last_file) plus the
   exception type and message, then re-raises so the original traceback
   surfaces and the exit code is non-zero.

Tests cover: SKIP_FILENAMES contents, the chunk-cap path returning
(0, room) with no upserts, and the new mine-aborted summary surfacing
both the partial counters and the exception class.

tests/test_miner.py

@@ -699,6 +699,83 @@ def test_mine_keyboard_interrupt_quotes_path_with_spaces_in_resume_hint(tmp_path
     assert f"mempalace mine {shlex.quote(str(project_root))}" in out
 
 
+def test_skip_filenames_includes_lockfiles():
+    """pnpm-lock.yaml and yarn.lock must be skipped alongside package-lock.json
+    so a Windows mine over a typical JS monorepo doesn't OOM the ONNX embedder
+    on a 24K-line lockfile (#1296)."""
+    from mempalace import miner
+
+    assert "package-lock.json" in miner.SKIP_FILENAMES
+    assert "pnpm-lock.yaml" in miner.SKIP_FILENAMES
+    assert "yarn.lock" in miner.SKIP_FILENAMES
+
+
+def test_process_file_skips_when_chunks_exceed_max(tmp_path, monkeypatch):
+    """A file producing more than MAX_CHUNKS_PER_FILE chunks must be skipped
+    with a clear message and zero upserts. Generated artifacts (CSVs, lock
+    files not in SKIP_FILENAMES) hit this — the cap is what prevents ONNX
+    bad_alloc on Windows when the embedder is asked to swallow thousands of
+    chunks in one batch (#1296)."""
+    from unittest.mock import MagicMock
+
+    from mempalace import miner
+
+    monkeypatch.setattr(miner, "MAX_CHUNKS_PER_FILE", 5)
+    over_cap = [{"content": f"chunk {i}", "chunk_index": i} for i in range(7)]
+    monkeypatch.setattr(miner, "chunk_text", lambda content, source_file: over_cap)
+
+    source = tmp_path / "huge.csv"
+    source.write_text("col1,col2\n" + "x,y\n" * 500, encoding="utf-8")
+    col = MagicMock()
+    col.get.return_value = {"ids": []}
+
+    drawers, room = miner.process_file(
+        source,
+        tmp_path,
+        col,
+        "wing",
+        [{"name": "general", "description": "General"}],
+        "agent",
+        False,
+    )
+
+    assert drawers == 0
+    col.upsert.assert_not_called()
+
+
+def test_mine_arbitrary_exception_prints_summary_and_reraises(tmp_path, capsys):
+    """A non-KeyboardInterrupt exception mid-mine must surface a summary
+    banner before propagating, so users don't see a silent exit-0 with no
+    completion message (#1296 Failure 2). Re-raise preserves the traceback
+    and yields a non-zero exit code."""
+    import pytest
+    from unittest.mock import patch
+
+    project_root = tmp_path / "proj"
+    project_root.mkdir()
+    _make_minable_project(project_root, n_files=4)
+    palace_path = project_root / "palace"
+
+    call_count = {"n": 0}
+
+    def fake_process_file(*args, **kwargs):
+        call_count["n"] += 1
+        if call_count["n"] == 2:
+            raise RuntimeError("simulated ONNX bad_alloc")
+        return (1, "general")
+
+    with patch("mempalace.miner.process_file", side_effect=fake_process_file):
+        with pytest.raises(RuntimeError, match="simulated ONNX bad_alloc"):
+            mine(str(project_root), str(palace_path))
+
+    out = capsys.readouterr().out
+    assert "Mine aborted by exception." in out
+    assert "files_processed: 1/" in out
+    assert "drawers_filed:" in out
+    assert "RuntimeError: simulated ONNX bad_alloc" in out
+    assert "upserted idempotently" in out
+
+
 def test_mine_cleans_up_pid_file_on_interrupt(tmp_path):
     """Our own PID entry in mine.pid is removed in the finally clause."""
     import pytest