feat: add lint and fix commands to the Makefile

[moliholy]

Summary

Add make lint and make fix commands that emulate the CI checks indico core follows, scoped to only changed files in the indico submodule. Covers Python (isort, unbehead, ruff) and JS/CSS (biome, eslint, tsc, stylelint) tooling.

Also adds the virtualenv to PATH via direnv so that indico's pre-commit hook can find the required binaries (ruff, python, isort).

[moliholy]

@OmeGak friendly ping.

[OmeGak]

I'm really not sure that this repository should have Makefile targets for the many different actions that we may want to run in Indico core or any of the plugins.

I have made my arguments in the PR from @duartegalvao that adds pylint to the repo (https://github.com/unconventionaldotdev/indicorp/pull/11/changes#r2782634229).

Each plugin directory is its own standalone project with its own architecture and QA decisions. This Makefile target breaks that isolation in ways that I'm not sure we should. If we did, then, why not also adding a target for building wheels, linting, another one for DB schema migrations, etc.?

I'm checking with Adrian if we can add a Makefile in Indico core. If we had it, the workflow would be:

cd indico
make lint

Which I think is very reasonable.

[OmeGak]

Rather than mangling the PATH, I would prefer that we rely on uv run.

[moliholy]

Then you have to run uv run git commit, because pre-commit hooks are triggered. I do not recommend that.

[OmeGak]

The pre-commit hook assumes that the virtualenv is active.

[moliholy]

I'm checking with Adrian if we can add a Makefile in Indico core. If we had it, the workflow would be:

If so, fine for me. But still, until that's done it doesn't hurt to have our own and then remove it. Not a string opinion at all either.

[OmeGak]

@ThiefMaster agreed with having a Makefile in Indico core with linting and test targets following a logic similar to this:

.PHONY: lint
lint: lint-py lint-js lint-locales lint-headers

.PHONY: lint-py
lint-py: lint-py-isort lint-py-ruff lint-py-backrefs

.PHONY: lint-py-isort
lint-py-isort:
	isort --check-only

.PHONY: lint-py-ruff
lint-py-ruff:
	ruff check --output-format=concise .

.PHONY: lint-py-backrefs
lint-py-backrefs:
	bin/maintenance/update_backrefs.py --ci

.PHONY: lint-js
lint-js:
	...

.PHONY: lint-locales
lint-locales:
	bin/maintenance/update_moment_locales.py --ci

.PHONY: lint-icons
lint-icons:
	bin/maintenance/generate_icons.py --ci

.PHONY: lint-headers
lint-headers:
	unbehead --check