Auto detected bugs - upload

# Upload App — Bug Report

## BUG 1: Checks the raw key instead of the looked-up value — condition is always False [MEDIUM]

**File:** `upload/vcf/vcf_import.py` ~line 80

```python
raw_data_type = request.GET.get("data_type")
data_type = DATA_TYPE_MAP.get(raw_data_type)
if raw_data_type is None: # BUG: should check data_type (the lookup result)
raise ValueError(...)
```

`raw_data_type` comes from `request.GET.get(...)` — if the key is missing, `raw_data_type` is `None` and the check fires correctly. But if the key is present with an *unrecognised* value (e.g., `?data_type=garbage`), `raw_data_type` is not `None`, so the guard is skipped, and `data_type` is silently `None` and used downstream. The check should test the *result* of the dictionary lookup.

**Fix:**

Dave Note: use walrus?

```python
if data_type is None:
raise ValueError(f"Unknown data_type: {raw_data_type!r}")
```

---

## BUG 2: Wrong exception class name — exception never caught, error handling silently skipped [HIGH]

**File:** `upload/views/views.py` ~line 103

```python
try:
vcf = uploaded_file.uploadedvcf
except UploadedVCF.RelatedObjectDoesNotExist: # BUG: wrong exception name
vcf = None
```

The correct exception for a missing reverse OneToOne relation is `UploadedVCF.DoesNotExist` (or `RelatedObjectDoesNotExist` raised from the *accessor*, not the model class). Using `UploadedVCF.RelatedObjectDoesNotExist` either raises `AttributeError` (no such attribute on the model class) or silently fails to catch the exception, letting it propagate uncaught.

**Fix:**

```python
try:
vcf = uploaded_file.uploadedvcf
except Exception: # or the correct RelatedObjectDoesNotExist from django.core.exceptions
vcf = None
```

More precisely:

```python
from django.core.exceptions import ObjectDoesNotExist

try:
vcf = uploaded_file.uploadedvcf
except ObjectDoesNotExist:
vcf = None
```