refactor: reorganize pxl8 into client/src/ module structure

- core/: main entry, types, logging, I/O, RNG
- asset/: ase loader, cart, save, embed
- gfx/: graphics, animation, atlas, fonts, tilemap, transitions
- sfx/: audio
- script/: lua/fennel runtime, REPL
- hal/: platform abstraction (SDL3)
- world/: BSP, world, procedural gen
- math/: math utilities
- game/: GUI, replay
- lua/: Lua API modules

src/pxl8_gen.h

@@ -1,45 +0,0 @@
-#pragma once
-
-#include "pxl8_bsp.h"
-#include "pxl8_types.h"
-
-typedef enum pxl8_procgen_type {
-    PXL8_PROCGEN_ROOMS,
-    PXL8_PROCGEN_TERRAIN
-} pxl8_procgen_type;
-
-typedef struct pxl8_procgen_params {
-    pxl8_procgen_type type;
-
-    i32 width;
-    i32 height;
-    i32 depth;
-    u32 seed;
-
-    i32 min_room_size;
-    i32 max_room_size;
-    i32 num_rooms;
-} pxl8_procgen_params;
-
-typedef struct pxl8_procgen_tex_params {
-    char name[16];
-    u32 seed;
-    i32 width;
-    i32 height;
-    f32 scale;
-    f32 roughness;
-    u8 base_color;
-    u8 variation;
-    u8 max_color;
-} pxl8_procgen_tex_params;
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-pxl8_result pxl8_procgen(pxl8_bsp* bsp, const pxl8_procgen_params* params);
-void pxl8_procgen_tex(u8* buffer, const pxl8_procgen_tex_params* params);
-
-#ifdef __cplusplus
-}
-#endif