Track src modules; stop ignoring .odin files

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/assets/assets.odin

@@ -0,0 +1,18 @@
+package assets
+
+import raylib "vendor:raylib"
+
+japanese_font: raylib.Font
+
+load_fonts :: proc() {
+    // Use raylib's default font for now
+    japanese_font = raylib.GetFontDefault()
+}
+
+unload_fonts :: proc() {
+    // Don't unload the default font
+}
+
+get_font :: proc() -> raylib.Font {
+    return japanese_font
+}