Never crash: frame-pool panic handler and ui-egui without expect()

ui-egui without expect()/unreachable!(): the frame pool is optional (rayon's global pool if the
OS refuses threads) and gets a panic_handler, because a panic in a rayon spawn() job aborts the
whole process by default; render-queue progress, the text-edit anchor and the GPU viewer
texture are bound where they're checked; the settings panel's Bool arm no longer panics.
Denies the panic lints in the crate.

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

clippy.toml

@@ -0,0 +1,4 @@
+allow-unwrap-in-tests = true
+allow-expect-in-tests = true
+allow-panic-in-tests = true
+allow-indexing-slicing-in-tests = true

crates/ui-egui/src/frames.rs

@@ -232,7 +232,8 @@ pub struct Frames {
     /// Pending jobs, picked by priority when a pool thread frees up (the viewer's frame first).
     queue: Arc<Mutex<Queue>>,
     #[cfg(not(target_arch = "wasm32"))]
-    pool: rayon::ThreadPool,
+    /// None if the OS refused the threads: jobs then go to rayon's global pool.
+    pool: Option<rayon::ThreadPool>,
     ctx: Option<egui::Context>,
     /// Render time of the last viewer (urgent) frame in ms, for the Info panel / perf readout.
     pub last_ms: Arc<Mutex<f64>>,
@@ -251,7 +252,14 @@ impl Default for Frames {
             inflight: Arc::new(Mutex::new(HashSet::new())),
             queue: Arc::new(Mutex::new(Queue::default())),
             #[cfg(not(target_arch = "wasm32"))]
-            pool: rayon::ThreadPoolBuilder::new().num_threads(threads).thread_name(|i| format!("ec-frame-{i}")).build().expect("frame pool"),
+            // A panicking job would abort the whole process (rayon's default for `spawn`): log it
+            // and lose only that frame (the panic hook has logged the message).
+            pool: rayon::ThreadPoolBuilder::new()
+                .num_threads(threads)
+                .thread_name(|i| format!("ec-frame-{i}"))
+                .panic_handler(|_| log::error!("a frame render panicked; that frame was skipped"))
+                .build()
+                .ok(),
             ctx: None,
             last_ms: Arc::new(Mutex::new(0.0)),
             content_keys: Arc::default(),
@@ -405,9 +413,13 @@ impl Frames {
         if self.remote.is_none() {
             let w = self.worker();
             // One spawn per job; each spawn renders whichever queued job matters most right now.
-            self.pool.spawn(move || {
+            let job = move || {
                 w.run_next();
-            });
+            };
+            match &self.pool {
+                Some(pool) => pool.spawn(job),
+                None => rayon::spawn(job),
+            }
         }
         #[cfg(target_arch = "wasm32")]
         if let Some(ctx) = &self.ctx {

crates/ui-egui/src/lib.rs

@@ -5,6 +5,8 @@
 //! Everything goes through `effectcraft_engine::Session::execute` (or `menus::invoke` for
 //! frontend-only commands) so every gesture is also available to agents.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod audio;
 pub mod automation;
 pub mod bench;

crates/ui-egui/src/panels/render_queue.rs

@@ -570,8 +570,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         lp.text(pos2(cx_num + 2.0, row.center().y), Align2::LEFT_CENTER, n.to_string(), Tokens::ui(12.0), t.text_dim);
         let name = comp_item.map(|i| i.name.clone()).unwrap_or_else(|| "(missing composition)".into());
         lp.text(pos2(cx_name + 2.0, row.center().y), Align2::LEFT_CENTER, &name, Tokens::ui(12.0), t.text);
-        let status = if rendering && progress.as_ref().and_then(|p| p.current) == Some(it.id) {
+        let status = if rendering && let Some(pr) = progress.as_ref().filter(|p| p.current == Some(it.id)) {
-            let pr = progress.as_ref().expect("progress");
             format!("Rendering {:.0}%", if pr.total > 0 { pr.done as f64 * 100.0 / pr.total as f64 } else { 0.0 })
         } else {
             it.status.label().to_string()

crates/ui-egui/src/panels/settings.rs

@@ -176,7 +176,8 @@ fn page_ui(app: &mut EffectcraftApp, ui: &mut egui::Ui, page: &Page, cur: &Value
                                     }
                                     r
                                 }
-                                Kind::Bool => unreachable!(),
+                                // Checkboxes are drawn above; nothing to edit here.
+                                Kind::Bool => ui.label(""),
                             };
                             resp = Some(r);
                         });

crates/ui-egui/src/panels/viewer_text.rs

@@ -193,8 +193,7 @@ pub fn hook(
                 handled = true;
             } else if e.contains(map, pos) {
                 let ci = e.hit(map, pos);
-                let sel = editing.as_ref().expect("editing");
+                let anchor = if mods.shift { editing.as_ref().map_or(ci, |sel| sel.anchor) } else { ci };
-                let anchor = if mods.shift { sel.anchor } else { ci };
                 exec(app, "text.setSelection", json!({"anchor": anchor, "caret": ci}));
                 typing_key(ui, true);
                 drag = Some(Drag::Select { layer: e.layer.id });

crates/ui-egui/src/panels/viewer_tools.rs

@@ -380,7 +380,7 @@ pub(crate) fn draw_frame(app: &mut EffectcraftApp, ctx: &egui::Context, painter:
     // read it back first (asynchronously in the browser: from the next frame on).
     let gpu = matches!((&app.viewer_shown, &app.viewer_native), (Some(s), Some(n)) if s.0 == n.0 && s.1 == n.1 && n.1.comp == cid.0);
     let rect = if gpu {
-        let id = app.viewer_shown.map(|s| s.0).expect("shown");
+        let Some(id) = app.viewer_shown.map(|s| s.0) else { return };
         if plain || app.viewer_pixels().is_none() {
             if !plain {
                 ctx.request_repaint();