feat: LuaJIT Animations (#1001)

## What are the changes about?
TL;DR:
![ly_meme](/attachments/f4c3a93b-6ede-42ab-a351-292e2105d4e2)

Slaps the entire LuaJIT runtime onto Ly, allowing for the creation of custom dynamic animations like GameOfLife, ColorWave, Doom, etc.
This PR adds the [ziglua](https://github.com/natecraddock/ziglua?ref=zig-0.16) dependency for its zig bindings and considerable buildtime config (mainly lua version selection).

### Example
 <video src="/attachments/3f91cf72-ae24-459c-8ef6-099f71e866fd" title="Screencast_20260519_172320" controls></video>
```lua
ly.frame_delay = 5
local timer = 0
local clock = os.clock()
local clock_diff = 0
function draw()
	timer = timer + 1
	byte = string.byte(' ')
	clock_diff = os.clock() - clock
	clock = os.clock()
	timer = timer + clock_diff
	for x = 0, ly.width-1 do
		for y = 0, ly.height-1 do
			local xc = 0xFF
			if x < 255 then xc = ((x + math.floor(timer / 2)) * 3) % 255 else xc = 0 end
			local yc = 0xFF
			if y < 255 then yc = ((y) * 3) % 255 else yc = 0 end
			ly.putCell(byte, xc, bit.bor(xc, yc), x, y)
		end
	end
end
```

### The API

The API that Ly gives to the user is minimal. A table is globally available, named `ly`, which provides the following:

| Member  | Purpose  |
|---------|---------|
| `ly.width` & `ly.height` | Respective Width/Height from the `TerminalBuffer` |
| `ly.putCell(byte, fg, bg, x, y)` | Literally `Cell.init(byte, fg, bg).put(x, y)`.|
| `ly.clock()` | The current real-time, in microseconds. |

### Error Handling

On a Lua Error, Ly won't quit but will instead paint the entire background red. The lua error in question can be found in the Ly log file and on-screen.
```log
2026-05-19 16:13:40 [err/Lua] Error (Cannot call draw()): attempt to call a nil value
2026-05-19 11:05:51 [err/Lua] Lua Error: ...dsammyt/programming/probe/ly/scratch/testConfig/test.lua:30: bad argument #1 to 'ipairs' (table expected, got number)
```

## Pre-requisites

- [X] I have tested & confirmed the changes work locally
- [X] I have run `zig fmt` throughout my changes

Reviewed-on: https://codeberg.org/fairyglade/ly/pulls/1001
Reviewed-by: AnErrupTion <anerruption+codeberg@disroot.org>

res/example.lua

@@ -0,0 +1,119 @@
+-- [[
+-- This is an example of using LuaJIT to create a custom animation in Ly, in this case
+-- bouncing squares that change colors.
+--
+-- You are given the following `ly` table:
+-- {
+--	height: number -- The height of the terminal
+--	width: number -- The width of the terminal
+--	putCell(byte, fg, bg, x, y) -- Draw a cell. 
+--      All arguments to this function are integers, and 
+--      must be in the unsigned 32-bit integer range: 0 to 2^32-1.
+--      If an argument cannot be converted to this range, it will throw
+--      an error.
+--
+--      For reference, the XY coordinates (0,0) draw a cell on the top-left 
+--      of the terminal, where the positive-X axis moves right and the
+--      positive-Y axis moves down.
+--
+--      For arguments fg and bg: they are colors in the format
+--      0xSSRRGGBB, where SS is for styling. See your
+--      config.ini for more details.
+--
+--      For the byte argument, you may use string.byte to fill this argument.
+--
+--	putCell(byte, fg, bg, x, y, w, h) -- Draw a rectangle. 
+--		Arguments are the same as putCell except for w and h, which are also
+--		unsigned integers. The rectangle will be drawn from the top-left, with
+--		argument w extending it to the right and argument h extending downwards.
+--
+--
+--  putLabel(str, fg, bg, x, y) -- Draw text in argument str. See putCell()
+--  	for info on the rest of the arguments.
+--
+--  clock() -- The time, in microseconds.
+-- }
+--
+-- A function named `draw()` must be declared in the script. This is ran every
+-- frame.
+--
+-- In addition to the base library, you are also given the following standard
+-- libraries:
+-- 	bit (A library exclusive to LuaJIT, see https://bitop.luajit.org/api.html)
+--	math
+--	string
+--	table
+--
+--	The std libraries io and debug are NOT included.
+-- 
+-- ]]
+
+-- You should probably copy FPS and FPS_COUNT into any future LuaJIT animations
+-- you create.
+local FPS_COUNT = 40
+local function FPS()
+	return (1/FPS_COUNT)*1000000
+end
+
+
+local SQUARE_WIDTH = 10
+local SQUARE_HEIGHT = 5
+
+local SQUARE_COUNT = 25
+
+local squares = {}
+
+for i = 1, SQUARE_COUNT do
+	local vx = 1
+	local vy = 1
+	if math.random(1, 2) == 2 then vx = -vx end
+	if math.random(1, 2) == 2 then vy = -vy end
+	squares[#squares+1] = {
+		x = math.random(1, ly.width - SQUARE_WIDTH),
+		y = math.random(1, ly.height - SQUARE_HEIGHT),
+		vx = vx,
+		vy = vy,
+		color = math.random(0xFFFFFF)
+	}
+end
+
+local timer = ly.clock()
+local perf = ly.clock()
+
+function draw()
+	-- Rather than progressing the animation by frame, do it based on
+	-- seconds, via ly.clock(). In this timeframe, you can update the animation
+	-- state.
+	-- DO NOT DRAW CELLS IN THIS TIMEFRAME. You will get flickering.
+
+	-- if this check passes, we can update the animation
+	if timer + FPS() < ly.clock() then 
+		for i, v in ipairs(squares) do
+			v.x = v.x + v.vx
+			v.y = v.y + v.vy
+			if v.x == 0 then 
+				v.vx = 1; v.color = math.random(0xFFFFFF)
+			end
+			if v.x + SQUARE_WIDTH >= ly.width-1 then
+				v.vx = -1; v.color = math.random(0xFFFFFF)
+			end
+			if v.y == 0 then 
+				v.vy = 1; v.color = math.random(0xFFFFFF)
+			end
+			if v.y + SQUARE_HEIGHT >= ly.height-1 then
+				v.vy = -1; v.color = math.random(0xFFFFFF) 
+			end
+		end
+		timer = ly.clock()
+	end
+
+
+	for i, v in ipairs(squares) do
+		ly.putRect(string.byte(' '), 0, v.color, v.x, v.y, SQUARE_WIDTH, SQUARE_HEIGHT)
+	end
+
+	local new_perf = ly.clock()
+	local str = "FT: "..((new_perf - perf) / 1000).."ms"
+	ly.putLabel(str , 0x00FFFFFF, 0, (ly.width/2) - (string.len(str)/2), ly.height-1)
+	perf = new_perf
+end