Segmentation fault during `ceph-osd --mkfs` with encryption enabled on ARM64 (MicroCeph 19.2.1)

### Summary

On ARM64 hardware (Raspberry Pi 5) running Debian 12 and MicroCeph 19.2.1, adding an **encrypted** OSD fails with a segmentation fault.
Unencrypted OSD creation works fine.

---

### Environment

| Component | Details |
|------------|----------|
| Hardware | Raspberry Pi 5 (BCM2712 / Cortex‑A76 / 8 GB RAM) |
| OS | Debian 12 (Bookworm), Kernel 6.12.47+rpt‑rpi‑2712 |
| Architecture | ARM64 (aarch64) |
| MicroCeph | 19.2.1+snap0b6e577483 (squid/edge channel, snap 1599) |
| Ceph Version | Squid 19.2.1 |
| Snapd | 2.71 |
| Storage | NVMe SSD [...], partition `/dev/nvme0n1p3` |

---

### Steps to Reproduce

1. Initialize MicroCeph and join cluster.
2. Verify `dm-crypt` plug is connected.
3. Run:

```
sudo microceph disk add /dev/nvme0n1p3 --wipe --encrypt
```

4. Observe daemon error.

---

### Actual Behavior

`ceph-osd --mkfs` crashes with a segfault:

```
Error: failed to bootstrap OSD: Failed to run: ceph-osd --mkfs --no-mon-config -i 1: signal: segmentation fault
```

No core dump is created even with `ulimit -c unlimited`.

---

### Expected Behavior

The OSD should initialize successfully using encryption.

---

### Additional Logs

```
Oct 20 16:48:51 [server] microceph.daemon: level=ERROR msg="failed to bootstrap OSD 1: failed to bootstrap OSD: Failed to run: ceph-osd --mkfs --no-mon-config -i 1: signal: segmentation fault"
```

No relevant kernel messages appear in `dmesg`.

---

### Troubleshooting Performed

- Verified `dm-crypt` kernel module loaded
- Connected snap plug and restarted `microceph.daemon`
- Tested on multiple Raspberry Pi 5 nodes
- No RAM issues (8 GB available)
- Unencrypted OSD creation works normally

---

### Hypotheses

- ARM64‑specific issue in Ceph encryption path
- Snap confinement mis‑mapping crypto syscalls
- BlueStore/BlueFS encryption crash regression
- Kernel 6.12 ARM64 crypto driver edge case

---

### Request

Can maintainers or community members confirm if encrypted OSD creation is currently supported/tested on ARM64?
Is there any workaround or recommended debug build to help analyze the segfault?