review(#1627): one UPDATEFIELD, honest counts, safe field boxes, one-pass host redraw

- UPDATEFIELD stays the command main already had (Select objects, undo,
  locale strings); it now takes the PR's reach — a block reference's
  attributes and block definition, a table's cell texts — and reports
  the fields that really changed. The PR's second implementation and its
  duplicate registration are gone.
- FIELDEVAL's range error goes through the locale catalog.
- Field boxes: no slicing inside a character, one layout per multi-line
  attribute, and TEXT boxes scale about the annotative reference point
  like the glyphs do. Comment and indentation put back where they belong.
- bump_text_hosts classifies every host in one pass over the drawing
  instead of scanning all layouts and blocks per host.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/entities/field.rs

@@ -327,7 +327,13 @@ pub const BACKGROUND: [f32; 4] = [203.0 / 255.0, 203.0 / 255.0, 203.0 / 255.0, 1
 
 /// Whether `entity` hosts a field: its extension dictionary has ACAD_FIELD.
 pub fn hosts_field(document: &CadDocument, entity: &codec::entities::EntityType) -> bool {
-    let Some(xdict) = entity.common().xdictionary_handle else {
+    common_hosts_field(document, entity.common())
+}
+
+/// [`hosts_field`] for an entity known only by its common data, such as an
+/// attribute of a block reference.
+pub fn common_hosts_field(document: &CadDocument, common: &codec::entities::EntityCommon) -> bool {
+    let Some(xdict) = common.xdictionary_handle else {
         return false;
     };
     matches!(