0.3.0: converge kernel onto upstream master

- Rebase all Red Bear kernel changes onto upstream master (4d5d36d4).
- Update version to 0.5.12+rb0.3.0 and add Red Bear author attribution.
- Switch redox_syscall direct dependency to local fork path (../syscall).
- Bump rust-toolchain.toml to nightly-2026-05-24.
- Regenerate Cargo.lock for +rb0.3.0 suffixes and path deps.

src/memory/mod.rs

@@ -112,9 +112,7 @@ pub fn allocate_p2frame_complex(
     freelist.for_orders[frame_order as usize] = next_free.frame();
 
     // TODO: Is this LIFO cache optimal?
-    // if min_order > 0 {
-    //     info!("MIN {min_order} FRAMEORD {frame_order}");
-    // }
+    //info!("MIN{min_order}FRAMEORD{frame_order}");
     for order in (min_order..frame_order).rev() {
         //info!("SPLIT ORDER {order}");
         let order_page_count = 1 << order;
@@ -233,9 +231,7 @@ pub unsafe fn deallocate_p2frame(orig_frame: Frame, order: u32) {
         old_head_info.set_prev(P2Frame::new(Some(new_head), largest_order));
     }
 
-    // if order > 0 {
-    //     info!("FREED {current:?}+2^{order}");
-    // }
+    //info!("FREED {frame:?}+2^{order}");
     freelist.used_frames -= 1 << order;
 }
 
@@ -559,7 +555,7 @@ fn init_sections(mut allocator: BumpAllocator<RmmA>) {
 
         assert_ne!(
             memory_map_area.size, 0,
-            "RMM should enforce areas are not of length 0"
+            "RMM should enforce areas are not zeroed"
         );
 
         // TODO: Should RMM do this?