chore: silence native and wasm build warnings

Gate target-specific code so neither build warns about the other's items:
native-only helpers (view, window icon, file dialogs, file association, plugin
host/guard/registry, self-update) are cfg'd to non-wasm; the wasm-only font
fallback (script_of / cjk_lang / request) is cfg'd to wasm. Drop an unused mut,
allow the few genuinely-conditional dead items (mesh_click_hit, GPU layout
helpers, parity stubs), and gate the embedded PlotSettings-unrelated dead
constants. Both targets now build clean (only the unavoidable nom/quick-xml
future-incompat dependency notice remains).

Co-Authored-By: Claude Opus 4.8 <[email protected]>

src/plugin/external.rs

@@ -79,6 +79,7 @@ pub fn plugins_dir() -> Option<PathBuf> {
 
 /// Delete an installed package's folder. It stays loaded for the current
 /// session (the library is resident); the removal takes effect on next start.
+#[cfg(not(target_arch = "wasm32"))]
 pub fn uninstall(id: &str) -> Result<(), String> {
     let dir = plugins_dir().ok_or("cannot locate the plugins folder")?.join(id);
     if dir.is_dir() {

src/plugin/host.rs

@@ -4,4 +4,5 @@
 // The session adapter the registry wraps `app` in to dispatch to plugins. The
 // plugin-facing contract — `BuiltinPlugin` + `HostApi` — lives in
 // `ocs_plugin_api`; external cdylibs target it directly.
+#[cfg(not(target_arch = "wasm32"))]
 pub(crate) use crate::app::plugin_host::HostSession;

src/plugin/mod.rs

@@ -16,6 +16,7 @@ pub(crate) use registry::try_dispatch;
 /// the cdylib boundary — it does NOT contain genuine UB (a plugin that
 /// segfaults or violates memory safety via `unsafe` can still crash the host;
 /// only out-of-process isolation would). (#145)
+#[cfg(not(target_arch = "wasm32"))]
 pub(crate) fn guard<T>(what: &str, f: impl FnOnce() -> T) -> Option<T> {
     match std::panic::catch_unwind(std::panic::AssertUnwindSafe(f)) {
         Ok(v) => Some(v),
@@ -38,12 +39,14 @@ pub(crate) fn guard<T>(what: &str, f: impl FnOnce() -> T) -> Option<T> {
 
 /// Process-wide queue of plugin-guard errors waiting to surface in the host's
 /// command-line history. Flushed by [`drain_errors`] from the app loop.
+#[cfg(not(target_arch = "wasm32"))]
 fn errors() -> &'static std::sync::Mutex<Vec<String>> {
     static E: std::sync::OnceLock<std::sync::Mutex<Vec<String>>> = std::sync::OnceLock::new();
     E.get_or_init(|| std::sync::Mutex::new(Vec::new()))
 }
 
 /// Take and return every queued plugin-guard error since the last drain.
+#[cfg(not(target_arch = "wasm32"))]
 pub(crate) fn drain_errors() -> Vec<String> {
     std::mem::take(&mut *errors().lock().unwrap())
 }

src/plugin/registry.rs

@@ -15,6 +15,7 @@ pub fn all_ribbon_modules() -> Vec<Box<dyn CadModule>> {
 pub fn ribbon_modules_enabled(
     disabled: &rustc_hash::FxHashSet<String>,
 ) -> Vec<Box<dyn CadModule>> {
+    #[cfg_attr(target_arch = "wasm32", allow(unused_mut))]
     let mut core = core_registry::all_modules();
     // Dynamically-loaded external plugins contribute tabs (their libraries stay
     // resident for the session, so these vtables remain valid).