fix frontend board mapping, game-over handling, and WASM-4

- fix Xform yx and add a shared view-aware board_position helper
- add GTK automatic game-over, restart, status, and multi-capture selection
- pin librsvg to the 2.60 series to match GTK4/glib 0.20
- add WASM orientation, undo/redo/new/flip controls, and winner overlay
- replace WASM crown images with canvas paths and remove dead files/deps
- make WASM-4 playable with mouse input, crowns, winner handling, and correct mapping
- move the WASM-4 release profile to the workspace root
- clean up frontend dead code and update the README

rdraught-w4/Cargo.toml

@@ -10,13 +10,7 @@ version.workspace = true
 
 [dependencies]
 wasm4.workspace = true
-wasm4-sys.workspace = true
 rdraught.workspace = true
 
 [lib]
 crate-type = ["cdylib"]
-
-[profile.release]
-opt-level = "z"
-lto = true
-