Lint with oxlint instead of ESLint

ESLint cannot parse this project's TypeScript: typescript@7 is the native port
with no JavaScript compiler API, which every ESLint TypeScript parser needs, and
typescript-eslint refuses to install with a >=4.8.4 <6.1.0 peer. oxlint parses
TypeScript without the compiler API, so it lints the .ts and the .js together in
about 20ms over the whole repo, and it runs the correctness category as errors.

It found one real thing on the first run: the drag harness built its fetch
options with a body key even for GET. The four opinionated rules it also flagged
are off with their reasoning in the README, since oxlint's config takes no
comments. lint is back in deploy.sh's checks, and the editor has lint tasks and
the oxc extension recommendation. Prettier is unchanged.

deploy.sh

@@ -25,7 +25,8 @@ if ! command -v podman >/dev/null 2>&1; then
 fi
 
 if [[ -z "${SKIP_CHECKS:-}" ]]; then
-  echo "==> format, types and tests"
+  echo "==> lint, format, types and tests"
+  npm run lint
   npm run format:check
   npm run typecheck
   npm test