Avoid sorting proto-palettes breaking mappings

The sorting was performed without updating the mappings, which broke the world.
We can instead sort the IDs as they are inserted into the packing queue,
which should also be faster than moving the actual proto-pal objects around.

src/gfx/process.cpp

@@ -574,6 +574,7 @@ public:
 		for (uint32_t x = 0; x < 8; ++x) {
 			row <<= 1;
 			uint8_t index = palette.indexOf(tile.pixel(x, y).cgbColor());
+			assert(index < palette.size()); // The color should be in the palette
 			if (index & 1) {
 				row |= 1;
 			}
@@ -948,12 +949,6 @@ contained:;
 		}
 	}
 
-	// Sort the proto-palettes by size, which improves the packing algorithm's efficiency
-	// We sort after all insertions to avoid moving items: https://stackoverflow.com/a/2710332
-	std::sort(
-	    protoPalettes.begin(), protoPalettes.end(),
-	    [](ProtoPalette const &lhs, ProtoPalette const &rhs) { return lhs.size() < rhs.size(); });
-
 	auto [mappings, palettes] = options.palSpecType == Options::NO_SPEC
 	                                ? generatePalettes(protoPalettes, png)
 	                                : makePalsAsSpecified(protoPalettes, png);