The pslua flake input was a dead local path (`/home/yura/...`), so the
dev shell could not be entered at all. Point it at
`github:Unisay/purescript-lua`, switch the dev shell to Lua 5.1 (it was
pinned to 5.3) and pin purs, matching the other package-set forks.

`packages.dhall` was on the ancient `psc-0.15.8` draft set, whose
`unsafe-coerce` (v6.0.0) ships an FFI value that is not parenthesised and
so trips pslua's foreign-file parser. Bump to the current set, which
carries `unsafe-coerce` v6.1.0, so the fork builds again.

CI moves onto the nix + overlay canon: build under `set -euo pipefail`,
luacheck `--std lua51 --no-unused-args` over the generated `dist/` (this
fork has no hand-written FFI of its own).

Align the flake with the other forks: purescript-overlay
(purs-bin.purs-0_15_16, spago-bin.spago-0_21_0, lua51Packages,
nixfmt-rfc-style, luaformatter, treefmt) instead of easy-purescript-nix,
and lock pslua to the current HEAD so dist/ is created on a clean build.

fix: point pslua at github, move to a current set + nix CI (#60)

Add the single agent instruction file (AGENTS.md) and the CLAUDE.md @-import
the set standardises on; this fork has no hand-written FFI so luacheck runs
over dist/. Drop dead .eslintrc.json/package.json, trim stale .gitignore
entries, bump the pslua pin to current main. Tooling and docs only.

chore: add AGENTS.md + CLAUDE.md, clean JS cruft

Repos moved from Unisay/* to the purescript-lua org. Update the pslua
flake input and lockfile owner (same rev 94c13ce), the packages.dhall
upstream-lua release URL, and the AGENTS.md links, so nothing relies on
the old-owner redirect.

chore: point pslua + package-set links at purescript-lua org

Wire treefmt via treefmt-nix: nixfmt, dhall format, purs-tidy (.tidyrc.json)
and LuaFormatter for the FFI (.lua-format, kept over StyLua because it
preserves the parentheses pslua's parser needs). `nix fmt` formats; the dev
shell installs a content-based pre-commit hook and CI runs
`nix fmt && git diff --exit-code` (content-based, since the in-place
formatters bump mtime and would trip treefmt --fail-on-change). Lua lines
budget 130 cols, matching the raised `luacheck --max-line-length`. This fork
has no hand-written FFI, so luacheck stays over the generated dist/.

chore: add treefmt formatting (nix fmt + pre-commit + CI check)

Replace the dev-shell installer that wrote .git/hooks/pre-commit with a
tracked .githooks/pre-commit wired via `git config core.hooksPath .githooks`.

Fixes three issues with the old hook: it gated on `[ -d .git ]` (false in
worktrees/submodules where .git is a file), it clobbered any existing
.git/hooks/pre-commit on every `nix develop`, and `nix fmt … || exit 0`
swallowed real formatter failures. The new hook skips only when `nix` is
absent (CI is the authoritative gate) and otherwise blocks on a `nix fmt`
failure or reformat.

The .spago/lua-unsafe-coerce/v6.0.0 gitlink was committed without a
.gitmodules entry, so a fresh checkout warns 'No url found for submodule
path'. It is build-cache junk; .spago is already covered by .gitignore.

Toolchain consistency: pin the pslua dev flake input to the current
compiler main across the ecosystem. flake.lock only; the package set
consumes sources + FFI, not this dev input, so no re-tag is needed.