chore: clean up compiler warnings — unused imports, variables, dead code

src/game.rs

@@ -1481,7 +1481,7 @@ impl Game {
                     }
                     let x = near_x + dx;
                     let y = near_y + dy;
-                    let sc = crate::world::worldgen::WORLD_SCALE;
+                    let _sc = crate::world::worldgen::WORLD_SCALE;
                     let clear_h = 8;
                     if !self.grid.in_bounds(x, y) || !self.grid.in_bounds(x, y - clear_h) {
                         continue;

src/ui/mod.rs

@@ -391,8 +391,6 @@ impl UiLayer {
         player_state: &crate::entity::player::Player,
     ) {
         let fs = self.font_scale;
-        let fh = self.fh();
-        let fw = self.fw();
         let w = 52 * fs / 2;
         let h = 62 * fs / 2;
         let bg = [22u8, 26, 38];

src/world/cellular.rs

@@ -1,11 +1,10 @@
-use crate::world::cell::{default_temp, Cell, MaterialId};
+use crate::world::cell::{Cell, MaterialId};
 use crate::world::chunk::CHUNK_SIZE;
 use crate::world::chunked_grid::ChunkedGrid;
 
 pub struct CellularAutomaton {
     tick: u64,
     rng_state: u64,
-    temps_buf: Vec<f32>,
     light_tick: u64,
 }
 
@@ -14,7 +13,6 @@ impl CellularAutomaton {
         Self {
             tick: 0,
             rng_state: 0x1234567890ABCDEF,
-            temps_buf: Vec::new(),
             light_tick: 0,
         }
     }
@@ -347,10 +345,10 @@ impl CellularAutomaton {
     }
 
     fn update_fire(&mut self, grid: &mut ChunkedGrid, x: i32, y: i32) {
-        let cell = grid.get(x, y);
+        let _cell = grid.get(x, y);
         let temp = grid.get_temp(x, y);
 
-        let (egt, egd) = grid.get_gas(x, y);
+        let (_egt, egd) = grid.get_gas(x, y);
         if egd < 200 {
             grid.set_gas(x, y, 3, (egd + 5).min(255));
         }