chromadb_rust_bindings SIGSEGV on macOS ARM64 (Python 3.14)

### What happened?

## Bug Report: chromadb_rust_bindings SIGSEGV on macOS ARM64 (Python 3.14)

**Package:** chromadb 1.5.8 (`chromadb_rust_bindings.abi3.so`)

**OS:** macOS 26.4.1 (Darwin 25.4.0), Apple Silicon ARM64

**Python:** 3.14.3 (Homebrew)

**Reproduces:** Every run, ~13s after startup

**Crash type:** `EXC_BAD_ACCESS (SIGSEGV)` — `KERN_INVALID_ADDRESS at 0x0000000000000088`

---

### Summary

Background thread in `chromadb_rust_bindings.abi3.so` segfaults with a null pointer dereference (offset +0x88). All frames in the triggered thread point to image index 50 (`chromadb_rust_bindings.abi3.so`) with no symbols resolved. Main thread is idle in `__psynch_cvwait`. Crash is deterministic and generates a macOS crash reporter dialog on every invocation.

**Also loaded:** onnxruntime 1.25.0, numpy, tokenizers

**Crash incident ID:** 7B4FC6EB-402A-42C3-B8B2-07BB49EB796E

---

### Expected Behavior

No crash.

### Actual Behavior

macOS crash reporter dialog every run, Python exits with SIGSEGV.

### Versions

chromadb 1.5.8, Python 3.14.3 (Homebrew), macOS 26.4.1 (Darwin 25.4.0) Apple Silicon ARM64; also loaded: onnxruntime 1.25.0, numpy, tokenizers

### Relevant log output

```shell

---
**Environment**
- Python: 3.14.3 (arm64, Homebrew: /opt/homebrew/...)
- chromadb: 1.5.8
- chromadb_rust_bindings: abi3.so (arm64)
- onnxruntime: 1.25.0
- OS: macOS 26.4.1 (25E253), Apple Silicon

**Crash**
- Type: EXC_BAD_ACCESS (SIGSEGV)
- Subtype: KERN_INVALID_ADDRESS at 0x0000000000000088
- Signal: SIGSEGV
- Raw codes: 0x0000000000000001, 0x0000000000000088
- Uptime at crash: ~13s
- Incident ID: 7B4FC6EB-402A-42C3-B8B2-07BB49EB796E

**Crashed thread** — all frames in chromadb_rust_bindings.abi3.so [image 50], no symbols:
0 chromadb_rust_bindings.abi3.so offset: 25958564
1 chromadb_rust_bindings.abi3.so offset: 25943260
2 chromadb_rust_bindings.abi3.so offset: 25931232
3 chromadb_rust_bindings.abi3.so offset: 9018588
4 chromadb_rust_bindings.abi3.so offset: 10211600
5 chromadb_rust_bindings.abi3.so offset: 10398672
6 chromadb_rust_bindings.abi3.so offset: 10160324
7 chromadb_rust_bindings.abi3.so offset: 10162124
8 chromadb_rust_bindings.abi3.so offset: 10398848
(repeating pattern continues)

**Main thread** — blocked in condition wait, called from chromadb_rust_bindings:
0 __psynch_cvwait
1 _pthread_cond_wait
2-9 chromadb_rust_bindings.abi3.so (no symbols, offsets: 24621764, 14167048, 16023340, 16783236, 14838104, 14790504, 14921160, 14786212)
10 method_vectorcall_VARARGS_KEYWORDS (Python)
11 PyObject_Vectorcall
12 _PyEval_EvalFrameDefault
... pymain_run_file → Py_RunMain → start

```

Start by reproducing the crash with chromadb 1.5.8, Python 3.14.3, and macOS ARM64, then inspect the unsymbolized frames in chromadb_rust_bindings.abi3.so and the reported crash details. The report names no source file or test; done means the deterministic SIGSEGV no longer occurs and Python exits normally.

Written by the indexing model from the issue text.