Remove birl dependency and use manual bindings

gleam.toml

···
 [dependencies]
 gleam_stdlib = ">= 0.44.0 and < 2.0.0"
 iv = ">= 1.3.2 and < 2.0.0"
-birl = ">= 1.8.0 and < 2.0.0"
 
 [dev-dependencies]
 gleeunit = ">= 1.0.0 and < 2.0.0"

manifest.toml

···
 ]
 
 [requirements]
-birl = { version = ">= 1.8.0 and < 2.0.0" }
 gleam_stdlib = { version = ">= 0.44.0 and < 2.0.0" }
 gleeunit = { version = ">= 1.0.0 and < 2.0.0" }
 iv = { version = ">= 1.3.2 and < 2.0.0" }

src/starfish.gleam

···
-import birl
 import gleam/bool
 import gleam/list
 import gleam/result
···
   let until = case cutoff {
     Depth(depth:) -> fn(current_depth) { current_depth > depth }
     Time(milliseconds:) -> {
-      let end_time = birl.monotonic_now() + milliseconds * 1000
-      fn(_) { birl.monotonic_now() >= end_time }
+      let end_time = monotonic_time() + milliseconds
+      fn(_) { monotonic_time() >= end_time }
     }
   }
 
   result.map(search.best_move(game.game, until), Move)
 }
+
+@external(erlang, "starfish_ffi", "monotonic_time")
+@external(javascript, "./starfish_ffi.mjs", "monotonic_time")
+fn monotonic_time() -> Int
 
 pub fn apply_move(game: Game, move: Move) -> Game {
   Game(move.apply(game.game, move.move))

src/starfish_ffi.erl

···
+-module(starfish_ffi).
+
+-export([monotonic_time/0]).
+
+monotonic_time() ->
+    StartTime = erlang:system_info(start_time),
+    CurrentTime = erlang:monotonic_time(),
+    Difference = (CurrentTime - StartTime),
+    erlang:convert_time_unit(Difference, native, millisecond).

src/starfish_ffi.mjs

···
+export function monotonic_time() {
+  return performance.now();
+}