Upgrade level editor for moon campaign support

Preserve tileset path and parallax style on save instead of
hardcoding tileset.png. Add tileset cycling (T key), tile flag
editing (F key for solid/platform/hazard/none), and 8x8 pixel
mini-icons for all entity types in the palette and canvas.

Fix entity palette not appearing when editor starts without a
prior level load by splitting entity_registry_init into populate
and init phases. Fix bitmap font rendering dropping the top row
by correcting FONT_H from 6 to 7. Widen toolbar button spacing.

Fix invisible collision from placed tiles lacking TileDefs by
calling ensure_tile_def on pencil and fill placement. Fix editor
hotkeys not working in the web build by latching key presses from
SDL_KEYDOWN events instead of comparing keyboard state snapshots.

src/engine/input.c

@@ -24,7 +24,6 @@ static int  s_mouse_scroll;
 
 /* ── Raw keyboard state ───────────────────────────── */
 static const Uint8 *s_key_state = NULL;
-static Uint8 s_prev_keys[SDL_NUM_SCANCODES];
 static Uint8 s_latched_keys[SDL_NUM_SCANCODES];
 
 /* Default key bindings (primary + alternate) */
@@ -53,7 +52,7 @@ void input_init(void) {
     memset(s_mouse_previous, 0, sizeof(s_mouse_previous));
     memset(s_mouse_latched_pressed, 0, sizeof(s_mouse_latched_pressed));
     memset(s_mouse_latched_released, 0, sizeof(s_mouse_latched_released));
-    memset(s_prev_keys, 0, sizeof(s_prev_keys));
+
     memset(s_latched_keys, 0, sizeof(s_latched_keys));
     s_mouse_x = s_mouse_y = 0;
     s_mouse_scroll = 0;
@@ -67,11 +66,6 @@ void input_poll(void) {
     s_quit_requested = false;
     s_mouse_scroll = 0;
 
-    /* Save previous raw key state */
-    if (s_key_state) {
-        memcpy(s_prev_keys, s_key_state, SDL_NUM_SCANCODES);
-    }
-
     /* Process SDL events */
     SDL_Event event;
     while (SDL_PollEvent(&event)) {
@@ -82,6 +76,16 @@ void input_poll(void) {
         case SDL_MOUSEWHEEL:
             s_mouse_scroll += event.wheel.y;
             break;
+        case SDL_KEYDOWN:
+            /* Latch raw key press directly from the event.
+             * More reliable than state-snapshot comparison,
+             * especially on Emscripten where SDL_GetKeyboardState
+             * may not reflect keys pressed within the same frame. */
+            if (!event.key.repeat &&
+                event.key.keysym.scancode < SDL_NUM_SCANCODES) {
+                s_latched_keys[event.key.keysym.scancode] = 1;
+            }
+            break;
         }
     }
 
@@ -102,15 +106,6 @@ void input_poll(void) {
         }
     }
 
-    /* Latch raw key edges */
-    if (s_key_state) {
-        for (int i = 0; i < SDL_NUM_SCANCODES; i++) {
-            if (s_key_state[i] && !s_prev_keys[i]) {
-                s_latched_keys[i] = 1;
-            }
-        }
-    }
-
     /* Read mouse state */
     Uint32 buttons = SDL_GetMouseState(&s_mouse_x, &s_mouse_y);
 

src/engine/tilemap.c

@@ -177,6 +177,7 @@ bool tilemap_load(Tilemap *map, const char *path, SDL_Renderer *renderer) {
 
     /* Load tileset texture */
     if (tileset_path[0] && renderer) {
+        snprintf(map->tileset_path, sizeof(map->tileset_path), "%s", tileset_path);
         map->tileset = assets_get_texture(tileset_path);
         if (map->tileset) {
             int tex_w;

src/engine/tilemap.h

@@ -47,6 +47,7 @@ typedef struct Tilemap {
     int          tile_def_count;
     SDL_Texture *tileset;
     int          tileset_cols;      /* columns in tileset image   */
+    char         tileset_path[ASSET_PATH_MAX]; /* tileset file path */
     Vec2         player_spawn;
     float        gravity;           /* level gravity (px/s^2), 0 = use default */
     char         music_path[ASSET_PATH_MAX]; /* level music file path          */