Merge origin/main into fix/issue-2092-camera-focus-crash

Conflicts were main's new code next to this branch's additions; both kept:
- crates/effects/src/lib.rs: main's Buf::pad_sides stays as main wrote it
  (Transform's transform_grow bounds that padding itself); Buf::pad keeps
  this branch's effective-pad clamp.
- crates/raster/src/lib.rs: main's quantize_px/round_half_up and this
  branch's MAX_PADDED_SIDE (still equal to limits::MAX_SIZE on main).

crates/render/src/three_d/compose.rs

@@ -197,7 +197,7 @@ fn mb_samples(r: &Renderer, ctx: &EvalCtx, layer: &Layer) -> usize {
 /// Prepare a layer (buffer, geometry, material). `None` when it shows nothing.
 pub(crate) fn prepare<'a>(r: &Renderer, ctx: &EvalCtx<'a>, layer: &'a Layer, order: usize, out: (u32, u32), in_run: bool) -> Option<Item<'a>> {
     let buf = r.blend_layer_buf(ctx, layer)?;
-    prepare_with(r, ctx, layer, order, out, in_run, buf, Mat4::IDENTITY)
+    prepare_with(r, ctx, layer, order, out, in_run, PlaneInput { buf, local: Mat4::IDENTITY })
 }
 
 /// Prepare a layer as planes: one per character for per-character 3D text, else one.
@@ -205,24 +205,21 @@ pub(crate) fn prepare_all<'a>(r: &Renderer, ctx: &EvalCtx<'a>, layer: &'a Layer,
     if crate::text::per_char_3d(ctx, layer) {
         return crate::text::per_char_planes(ctx, layer, r.opts.scale)
             .into_iter()
-            .filter_map(|(buf, m)| prepare_with(r, ctx, layer, order, out, in_run, r.to_blend(Arc::new(buf), None), m))
+            .filter_map(|(buf, m)| prepare_with(r, ctx, layer, order, out, in_run, PlaneInput { buf: r.to_blend(Arc::new(buf), None), local: m }))
             .collect();
     }
     prepare(r, ctx, layer, order, out, in_run).into_iter().collect()
 }
 
-/// Prepare a plane showing `buf`, whose space maps into the layer through `local`.
-#[allow(clippy::too_many_arguments)]
-fn prepare_with<'a>(
-    r: &Renderer,
-    ctx: &EvalCtx<'a>,
-    layer: &'a Layer,
-    order: usize,
-    out: (u32, u32),
-    in_run: bool,
-    mut buf: Arc<Buf>,
+/// A processed plane and its mapping into the layer's coordinate system.
+struct PlaneInput {
+    buf: Arc<Buf>,
     local: Mat4,
-) -> Option<Item<'a>> {
+}
+
+/// Prepare the plane's geometry, motion samples and material.
+fn prepare_with<'a>(r: &Renderer, ctx: &EvalCtx<'a>, layer: &'a Layer, order: usize, out: (u32, u32), in_run: bool, plane: PlaneInput) -> Option<Item<'a>> {
+    let PlaneInput { mut buf, local } = plane;
     if buf.img.is_empty() {
         return None;
     }