check cli dependencies at startup

from pathlib import Path

import os

import tempfile

from shutil import which

import sys

for tool in [

    "vips",

    "convert",

    "exiftool",

    "pdftoppm",

    "pdftotext",

    "tesseract",

]:

    if not Path(which(tool) or "/does/not/exist").exists():

        sys.exit(f"Couldn't find tool {tool}, please read installation instructions.")

DEFAULT_AUTO_FIELD = "django.db.models.AutoField"

BASE_DIR = Path(__file__).resolve().parent.parent