fix: stabilize web loading and paper rendering

src/app/document.rs

@@ -228,6 +228,7 @@ pub(super) struct DocumentTab {
     pub(super) last_synced_camera_gen: u64,
     /// Render-state key of `scene.document.preview`. Matching saves reuse the
     /// encoded DWG thumbnail instead of rescanning every resident wire.
+    #[cfg(not(target_arch = "wasm32"))]
     pub(super) thumbnail_cache_key: Option<super::ThumbnailCacheKey>,
     /// Sentinel "Welcome / Start" tab. Always at index 0 when present.
     /// Cannot be closed; the viewport area renders a welcome page instead
@@ -463,6 +464,7 @@ impl DocumentTab {
             block_edit: None,
             active_mleader_style: "Standard".to_string(),
             last_synced_camera_gen: 0,
+            #[cfg(not(target_arch = "wasm32"))]
             thumbnail_cache_key: None,
             is_start: false,
             pan_mode: false,

src/app/mod.rs

@@ -755,7 +755,9 @@ pub(super) struct OpenCADStudio {
     pending_close: Option<PendingClose>,
     /// Latest save job per stable tab id. Older completions may finish, but
     /// cannot mark a newer document state clean or redirect its path.
+    #[cfg(not(target_arch = "wasm32"))]
     active_save_jobs: std::collections::HashMap<u64, u64>,
+    #[cfg(not(target_arch = "wasm32"))]
     save_job_serial: u64,
     /// OS window for the unsaved-changes confirmation dialog.
 
@@ -866,6 +868,7 @@ pub(super) enum PendingClose {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg(not(target_arch = "wasm32"))]
 pub(super) enum SavePurpose {
     Manual,
     SaveAs,
@@ -873,6 +876,7 @@ pub(super) enum SavePurpose {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg(not(target_arch = "wasm32"))]
 pub(super) enum SaveContinuation {
     None,
     CloseTab,
@@ -880,6 +884,7 @@ pub(super) enum SaveContinuation {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg(not(target_arch = "wasm32"))]
 pub(super) struct ThumbnailCacheKey {
     epoch: u64,
     camera_generation: u64,
@@ -889,6 +894,7 @@ pub(super) struct ThumbnailCacheKey {
 }
 
 #[derive(Debug, Clone)]
+#[cfg(not(target_arch = "wasm32"))]
 pub struct SaveOutcome {
     job_id: u64,
     tab_id: u64,
@@ -1463,6 +1469,7 @@ pub enum Message {
     /// Periodic autosave tick — write `.sv$` recovery files for dirty tabs.
     AutoSave,
     /// Native background save/autosave completed.
+    #[cfg(not(target_arch = "wasm32"))]
     SaveFinished(SaveOutcome),
     // ─────────────────────────────────────────────────────────────────────
     CommandInput(String),
@@ -2505,7 +2512,9 @@ impl OpenCADStudio {
             active_interaction_index: None,
             queued_interaction_indices: std::collections::VecDeque::new(),
             pending_close: None,
+            #[cfg(not(target_arch = "wasm32"))]
             active_save_jobs: std::collections::HashMap::new(),
+            #[cfg(not(target_arch = "wasm32"))]
             save_job_serial: 0,
             save_dialog_format: "DWG 2018".to_string(),
             save_dialog_filename: "drawing.dwg".to_string(),

src/app/update/file.rs

@@ -783,7 +783,7 @@ pub(super) fn on_open_file(&mut self) -> Task<Message> {
                 )
             })
         };
-        let clone_started = std::time::Instant::now();
+        let clone_started = iced::time::Instant::now();
         let mut snapshot = self.tabs[i].scene.document.clone();
         let clone_ms = clone_started.elapsed().as_secs_f64() * 1000.0;
         if crate::perf::enabled() {
@@ -807,7 +807,7 @@ pub(super) fn on_open_file(&mut self) -> Task<Message> {
                 let (result, refreshed_preview) = std::thread::spawn(move || {
                     let mut refreshed_preview = None;
                     if let Some((wires, camera, bg_color, png, viewport)) = thumbnail {
-                        let started = std::time::Instant::now();
+                        let started = iced::time::Instant::now();
                         snapshot.preview = crate::io::thumbnail::from_snapshot(
                             &wires,
                             &camera,

src/app/update/mod.rs

@@ -3954,9 +3954,6 @@ impl OpenCADStudio {
             #[cfg(not(target_arch = "wasm32"))]
             Message::SaveFinished(outcome) => self.on_save_finished(outcome),
 
-            #[cfg(target_arch = "wasm32")]
-            Message::SaveFinished(_) => Task::none(),
-
             // ── Page Setup ────────────────────────────────────────────────
             Message::UpdateCheckResult(latest) => {
                 let Some(info) = latest else {

src/app/update/viewport.rs

@@ -3639,7 +3639,7 @@ impl OpenCADStudio {
         let weak = Arc::downgrade(&wires);
         Some(Task::perform(
             async move {
-                let started = std::time::Instant::now();
+                let started = iced::time::Instant::now();
                 let index = Arc::new(
                     crate::scene::pick::interaction_index::InteractionIndex::build(&wires),
                 );