The `time`/`timeLog`/`timeEnd` FFI stubs took a label parameter `s` but
never used it (the stub just errors), so luacheck flagged an unused
argument. Rename it to `_s` to mark it deliberately unused; the stubs
still fail loudly because Lua has no console-timer equivalent.

Also moves CI off the dead npm/bower/setup-purescript flow onto the nix
+ overlay canon used by the other package-set forks: `scripts/build`
under `set -euo pipefail`, luacheck `--std lua51 --no-unused-args`, and
drops the broken pulp/node `scripts/test`.

CI built on a 2024-03 pslua pin that wrote --lua-output-file without
creating the parent dir, so a fresh checkout failed with
`dist/Effect_Console.lua: withFile: does not exist`. Current pslua
ensures the output dir exists (the withOutputFile fix).

fix: stop ignoring timer labels with a named arg, move CI to nix (#64)

Move the dev shell off easy-purescript-nix onto the shared
purescript-overlay (purs 0.15.16, spago 0.21.0, lua51). Add AGENTS.md as
the single agent instruction file + CLAUDE.md @-import. Drop dead JS-era
files. Tooling and docs only.

chore: migrate flake to the purescript-overlay canon, add AGENTS.md

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`. The bulk
of the diff is the first format pass.

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.

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.

Upstream purescript-console maps `error` and `warn` to console.error /
console.warn, which target stderr in Node; the Lua FFI routed both through
`print` (stdout), erasing the only behavioral distinction they have from
`log` and breaking consumers that separate the streams. They now use
`io.stderr:write`. `log`/`info`/`debug` stay on stdout (correct — Node's
console.log/info/debug all target stdout).

Adds a Lua 5.1 regression guard (test/regression/console.lua) and a
scripts/test runner.

Fixes purescript-lua/purescript-lua#76
Fixes purescript-lua/purescript-lua#77