The native formatting functions in src/Data/Number/Format.lua passed an
unbound variable `number` to string.format while the actual Number argument
was bound as `n`. At runtime `number` resolved to a nil global, so
toPrecisionNative/toFixedNative/toExponentialNative errored instead of
formatting their input. Reference each function's real argument `n`.

Closes purescript-lua#1

fix: use bound argument n in Format.lua FFI instead of unbound number

…pts/build, run test via bash)

chore: normalize build tooling (purescript-overlay, nix CI, Lua 5.1)

AGENTS.md is the single instruction file the coding agents read natively;
CLAUDE.md is a one-line @AGENTS.md import so Claude Code shares it. Also
removes dead bower.json/package.json/.eslintrc.json. CI is already on the
shared canon; no src/ change.

chore: add AGENTS.md, drop dead JavaScript-era files

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.

string.format("%.<d>d", n) is integer formatting, so toFixed dropped the
fractional part (e.g. toFixed 2 3.14159 -> garbage). Use %f for fixed-point
decimals. Fixes purescript-lua#3.

Verified under Lua 5.1 (3.14159->3.14, 3.7@0->4, 2.5@3->2.500, 10@2->10.00).

Aligns the FFI with the modules' own docstrings (the JS Number semantics):

- toPrecisionNative used %f (d digits after the point); JS toPrecision is
  d SIGNIFICANT digits, so it was wrong for every input and destroyed small
  magnitudes (precision 3 of 0.000123456 gave "0.000"). Now uses %g.
- fromStringImpl wrapped tonumber's nil in Just on a parse failure (a
  Just Number holding nil) and ignored the supplied isFinite predicate. It
  now extracts a leading numeric prefix (matching parseFloat's tolerance of
  a whitespace prefix and trailing junk, e.g. "  1.2 ??" -> Just 1.2),
  guards the parse, and uses isFinite, so "bad"/"" -> Nothing.
- sign encoded the result through the boolean condition, so sign 0 returned
  the boolean `true` instead of the Number 0. Now uses explicit branches.
- max/min folded with Lua's >/< which drop NaN, so e.g. max 1 NaN gave 1;
  JS Math.max/min return NaN if either argument is NaN. Added a NaN guard.
- toExponentialNative emitted C's zero-padded exponent (1.23e+03); JS uses
  the minimal exponent width (1.23e+3). Strips one leading exponent zero.
- toString spelled the specials "inf"/"-inf"/"nan"; now "Infinity"/
  "-Infinity"/"NaN". (Finite values keep Lua's %.14g formatting — the JS
  shortest-round-trip form is out of scope; see #99 / accepted divergences.)

Extends test/regression/format.lua and adds test/regression/number.lua.

Fixes purescript-lua/purescript-lua#92
Fixes purescript-lua/purescript-lua#93
Fixes purescript-lua/purescript-lua#94
Fixes purescript-lua/purescript-lua#95
Fixes purescript-lua/purescript-lua#96
Fixes purescript-lua/purescript-lua#97
Fixes purescript-lua/purescript-lua#98