Use the venv on backend/venv/

DO NOT mess with the system's python

For Frontend work:

read both Frontend Design related Markdown files on the frontend/ folder

For anything touching e621 endpoints or payloads (posts, pools, tags, users,
favorites, IQDB, blacklists, uploads), consult the e621 OpenAPI spec first:
    https://e621.wiki/openapi.yaml

Download it once per session (it is ~450 KB YAML), then grep it for the exact
path/parameter/schema names instead of guessing:

    curl -sL https://e621.wiki/openapi.yaml -o /tmp/opencode/e621-openapi.yaml
    grep -n "^  /pools.json" /tmp/opencode/e621-openapi.yaml

Notes learned from the spec (verify before trusting):
- Index endpoints often return a bare array (e.g. GET /pools.json) while the
  show endpoint returns the object directly (e.g. GET /pools/{id}.json) — not
  always wrapped in a named key.
- Pools index supports search[order] (id_asc, id_desc, name, created_at,
  post_count), search[name_matches], search[category], search[is_active].
- Own settings (including user[blacklisted_tags]) are updated with
  PATCH /users/{id}.json as form-encoded data; /users/me.json returns the user
  object at the top level.

Project constraints (do not regress):
- Backend is Django 6 + DRF with token auth (no session auth on the API);
  MariaDB/Redis come from docker-compose.yml.
- No server-side media processing: the home server cannot handle it.
  Compression/optimization runs client-side (WebCodecs + WASM in a worker)
  and the server only applies the result via POST /api/files/J-x/optimize/.
- Do not use imgdd; perceptual hashing is imagehash server-side.
- Chat/messaging features are out of scope.