Merge upstream/main into fix-1083-beat-marker-audio-pause

Conflicts came from upstream splitting crates/project/src/lib.rs and moving the
frames tests. Re-applied the branch's change in the new places:
- Layer::same_pixels_with now in crates/project/src/layer.rs
- Comp::same_pixels_with, same_settings(o, with_markers), pixel_form_with and the
  timing-marker helpers in crates/project/src/comp.rs (same_pixels_ignoring_markers
  stays removed)
- Project::reads_markers in crates/project/src/item.rs
- crates/ui-egui/src/frames.rs uses reads_markers/same_pixels_with; the branch's
  two marker tests replace the old ones in crates/ui-egui/src/frames/tests.rs

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

crates/render/src/disk_cache.rs

@@ -331,7 +331,7 @@ impl DiskCache {
                 let Ok(files) = std::fs::read_dir(shard.path()) else { continue };
                 for f in files.flatten() {
                     let p = f.path();
-                    let name = p.file_name().and_then(|n| n.to_str()).unwrap_or("");
+                    let name = p.file_name().and_then(std::ffi::OsStr::to_str).unwrap_or("");
                     if name.contains(".tmp") {
                         // A writer that died mid-write; old temporaries are removed.
                         if f.metadata().and_then(|m| m.modified()).is_ok_and(|t| t.elapsed().is_ok_and(|e| e.as_secs() > 600)) {