model: geometry names up to 64 KiB everywhere, so long persistent face names mesh

Persistent names grow with a design's split history; opening accepted them but mesh tags, sets
and loads capped geometry names at 256 characters. One cap (64 KiB, against hostile input)
now holds for geometry references, partitions and saved views.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/io/src/lib.rs

@@ -179,8 +179,8 @@ pub struct Geometry {
 /// Most items a view hides.
 pub const MAX_HIDDEN: usize = 100_000;
 
-/// Longest name of a hidden item.
-const MAX_HIDDEN_NAME: usize = 1024;
+/// Longest name of a hidden item (a body's name is a geometry name).
+const MAX_HIDDEN_NAME: usize = fieldcraft_model::geometry::MAX_GEOMETRY_NAME_LEN;
 
 /// The kinds of items the viewport draws one by one, and so can hide.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]