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/model/src/datums.rs

@@ -11,14 +11,13 @@ use std::collections::BTreeMap;
 
 use serde::{Deserialize, Serialize};
 
+use crate::geometry::MAX_GEOMETRY_NAME_LEN;
 use crate::{Error, Model, Result, check_name, context, insert_new, not_in_use, remove_existing, replace_existing};
 
 /// Most partitions a model holds.
 pub const MAX_PARTITIONS: usize = 256;
 /// Most bodies one partition names.
 pub const MAX_PARTITION_BODIES: usize = 1000;
-/// Longest body name a partition holds.
-const MAX_BODY_NAME: usize = 256;
 
 /// A datum plane, axis or point.
 #[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
@@ -163,8 +162,8 @@ impl Model {
             return Err(invalid(format!("at most {MAX_PARTITION_BODIES} bodies")));
         }
         for (i, b) in partition.bodies.iter().enumerate() {
-            if b.trim().is_empty() || b.len() > MAX_BODY_NAME {
-                return Err(invalid(format!("body names are 1 to {MAX_BODY_NAME} characters")));
+            if b.trim().is_empty() || b.len() > MAX_GEOMETRY_NAME_LEN {
+                return Err(invalid(format!("body names are 1 to {MAX_GEOMETRY_NAME_LEN} bytes")));
             }
             if partition.bodies.get(..i).is_some_and(|before| before.contains(b)) {
                 return Err(invalid(format!("body `{b}` is listed twice")));