feat(display): plugin entity-class labels in the panel, records, and automation

Resolve entities' XDATA class-identity keys through the live plugin manager
(new `src/plugin/entity_labels.rs`) and qualify display types as
"<Label> (<Native>)" wherever the bare native type is shown today.

- The single-entity Properties panel title (and the node graph, which shares
  the same computation) becomes e.g. "Linear Element (Line)". Host-owned
  classifications (xref, dynamic constraints, underlays, surfaces) keep the
  native parenthesized part, so nothing they tell the user is lost.
- The records API's `entities` collection: `display_type` carries the
  qualified label; the raw `type` / `record_type` fields stay native so
  existing scripts, type filters, and by-type grouping keep working.
- The automation entity summary gains a `display_type` field with the same
  semantics; `type` stays raw. Exposed by `query`, `user_select` sessions,
  and `get_selection`.

Semantics: the identity (a stable class KEY like "CVIFC-CLASS:LINE") lives
in the entity's XDATA and round-trips the drawing; the display LABELS live
in the declaring plugin's manifest. Keys only — no display text is ever
written to the file, and the label never governs behavior (display-only: it
does not affect snapping, selection, filtering, or grouping). Gating rides
live manager state at query time, so without a loaded declaring plugin every
surface here is byte-identical to today, immediately after any reopen, with
no re-assert pass. The command-line LIST output deliberately stays on the raw
dxf name. An app id claimed by more than one loaded plugin resolves through
the first-loaded declaration and debug-logs the ignored duplicate; a
prefix-only value, an unknown key, or an empty label mapping fall back to
the native type.

Tests: resolver core (known key, foreign app ignored, record without an
identity value ignored, prefix-only / unknown key / empty label fallback,
duplicate app id first-wins), the empty-manager gating end-to-end through
`with_manager`, the "<Label> (<Native>)" form, and the byte-identical
fallbacks asserted at the panel, records, and query layers for entities
stamped with a perfect identity record.

src/app/automation.rs

@@ -257,12 +257,25 @@ pub(crate) fn entity_type_matches(entity: &codec::EntityType, requested: &str) -
 
 /// One entity as JSON. Summary mode carries identity only, geometry adds the
 /// entity's defining values, and full also includes its world bounds.
-pub(crate) fn entity_json(e: &codec::EntityType, detail: &str) -> Value {
+///
+/// `custom_label` is the plugin-declared class label for the entity's XDATA
+/// class identity, if a live declaring plugin provides one; it surfaces as
+/// `display_type` ("`<Label>` (`<Native>`)"), while `type` stays the raw
+/// native name so existing scripts and filters keep working.
+pub(crate) fn entity_json(
+    e: &codec::EntityType,
+    detail: &str,
+    custom_label: Option<String>,
+) -> Value {
     use codec::EntityType as E;
     let c = e.common();
     let mut obj = json!({
         "handle": format!("{:X}", c.handle.value()),
         "type": crate::entities::names::ui_name(e),
+        "display_type": crate::plugin::entity_labels::display_type_title(
+            custom_label,
+            crate::entities::names::ui_name(e).to_string(),
+        ),
         "layer": c.layer,
     });
     if detail == "summary" {
@@ -1343,7 +1356,11 @@ impl OpenCADStudio {
             if near.is_some() && nearest.is_none() {
                 continue;
             }
-            let mut entity = entity_json(e, detail);
+            let mut entity = entity_json(
+                e,
+                detail,
+                crate::plugin::entity_labels::custom_entity_class_label(&self.disabled_plugins, e),
+            );
             if let Some(nearest) = nearest {
                 let object = entity.as_object_mut().expect("entity JSON object");
                 object.insert("distance".into(), json!(nearest.distance));
@@ -4319,4 +4336,42 @@ mod tests {
             .expect("second ready banner");
         assert!(banner2.contains("ready"), "{banner2}");
     }
+
+    #[test]
+    fn entity_json_display_type_is_native_without_a_label() {
+        let entity = codec::EntityType::Point(codec::entities::Point::new());
+        let json = super::entity_json(&entity, "summary", None);
+        assert_eq!(json["type"], "Point");
+        assert_eq!(json["display_type"], "Point");
+    }
+
+    #[test]
+    fn entity_json_display_type_qualifies_the_label() {
+        let entity = codec::EntityType::Point(codec::entities::Point::new());
+        let json = super::entity_json(&entity, "summary", Some("Survey Point".to_string()));
+        assert_eq!(json["type"], "Point");
+        assert_eq!(json["display_type"], "Survey Point (Point)");
+    }
+
+    #[test]
+    fn query_reports_native_display_type_for_plugin_classed_entities() {
+        // End-to-end through the automation query surface: an entity stamped
+        // with a plugin class identity keeps the native display while no
+        // declaring plugin is loaded (labels activate only through the live
+        // plugin manager, which the test harness does not populate).
+        let mut app = super::OpenCADStudio::new_for_test();
+        app.automation_op(r#"{"op":"new"}"#);
+        let i = app.active_tab;
+        let mut entity = codec::EntityType::Point(codec::entities::Point::new());
+        let mut record = codec::xdata::ExtendedDataRecord::new("CVIFC");
+        record.add_value(codec::xdata::XDataValue::String(
+            "CVIFC-CLASS:POINTMARK".to_string(),
+        ));
+        entity.common_mut().extended_data.add_record(record);
+        app.tabs[i].scene.add_entity(entity);
+
+        let query = app.automation_op(r#"{"op":"query","type":"Point"}"#);
+        assert_eq!(query["entities"][0]["type"], "Point");
+        assert_eq!(query["entities"][0]["display_type"], "Point");
+    }
 }

src/app/control/interactive.rs

@@ -191,7 +191,16 @@ impl OpenCADStudio {
                     .scene
                     .document
                     .get_entity(*handle)
-                    .map(|entity| entity_json(entity, &session.detail))
+                    .map(|entity| {
+                        entity_json(
+                            entity,
+                            &session.detail,
+                            crate::plugin::entity_labels::custom_entity_class_label(
+                                &self.disabled_plugins,
+                                entity,
+                            ),
+                        )
+                    })
             })
             .collect();
         let count = entities.len();
@@ -359,11 +368,11 @@ impl OpenCADStudio {
 
     /// `get_selection` — read-only snapshot of the active tab's selection
     /// (the read-back half of the `user_select` sampling flow). `handle`,
-    /// `type`, `layer` and `bounds` come straight from the `query` output so
-    /// clients share one parser; `text`/`value` expose the stripped and raw
-    /// strings for TEXT/MTEXT, and `block`/`position` identify an INSERT's
-    /// block definition and insertion point (null otherwise). Reads
-    /// `scene.selection` and never mutates it.
+    /// `type`, `display_type`, `layer` and `bounds` come straight from the
+    /// `query` output so clients share one parser; `text`/`value` expose the
+    /// stripped and raw strings for TEXT/MTEXT, and `block`/`position`
+    /// identify an INSERT's block definition and insertion point (null
+    /// otherwise). Reads `scene.selection` and never mutates it.
     pub(in crate::app) fn control_get_selection(&self) -> Value {
         let scene = &self.tabs[self.active_tab].scene;
         let entities: Vec<Value> = scene
@@ -371,10 +380,18 @@ impl OpenCADStudio {
             .iter()
             .filter_map(|handle| {
                 scene.document.get_entity(*handle).map(|entity| {
-                    let full = entity_json(entity, "full");
+                    let full = entity_json(
+                        entity,
+                        "full",
+                        crate::plugin::entity_labels::custom_entity_class_label(
+                            &self.disabled_plugins,
+                            entity,
+                        ),
+                    );
                     json!({
                         "handle": full["handle"],
                         "type": full["type"],
+                        "display_type": full["display_type"],
                         "layer": full["layer"],
                         "bounds": full["bounds"],
                         "text": full.get("text").cloned().unwrap_or(Value::Null),

src/app/properties.rs

@@ -1752,6 +1752,19 @@ impl OpenCADStudio {
             }
             None => title,
         };
+
+        // A plugin-declared class identity (API v10) qualifies the title as
+        // "<Label> (<Native>)" while one of the live loaded plugins declares
+        // a label for this entity's XDATA class key; without one the title is
+        // exactly the native type. Display-only — the key round-trips the
+        // drawing, the label never does.
+        let title = crate::plugin::entity_labels::display_type_title(
+            crate::plugin::entity_labels::custom_entity_class_label(
+                &self.disabled_plugins,
+                source_entity,
+            ),
+            title,
+        );
         (sections, title)
     }
 
@@ -5058,3 +5071,40 @@ mod aggregation_tests {
         assert!(format!("{:?}", layer.value).contains("WALLS"));
     }
 }
+
+#[cfg(test)]
+mod custom_class_title_tests {
+    // Plugin-declared class labels (API v10) qualify the single-entity panel
+    // title as "<Label> (<Native>)" only while a declaring plugin is loaded.
+    // The test harness never loads plugins, so the observable behavior here is
+    // the gating: an entity stamped with a perfect identity record (registered
+    // app, class-prefix key) still shows today's exact native title. The
+    // "<Label> (<Native>)" form itself is covered by
+    // plugin::entity_labels::display_type_title, and the live-manager
+    // filtering by plugin::process::manager tests.
+    use crate::app::OpenCADStudio;
+
+    #[test]
+    fn single_entity_title_stays_native_without_a_loaded_plugin() {
+        let mut app = OpenCADStudio::new_for_test();
+        let i = app.active_tab;
+        let mut entity = codec::EntityType::Line(codec::entities::Line::from_points(
+            codec::types::Vector3::ZERO,
+            codec::types::Vector3::new(1.0, 0.0, 0.0),
+        ));
+        let mut record = codec::xdata::ExtendedDataRecord::new("CVIFC");
+        record.add_value(codec::xdata::XDataValue::String(
+            "CVIFC-CLASS:LINE".to_string(),
+        ));
+        entity.common_mut().extended_data.add_record(record);
+        let handle = app.tabs[i].scene.add_entity(entity);
+
+        let source = app.tabs[i]
+            .scene
+            .document
+            .get_entity(handle)
+            .expect("committed line");
+        let (_, title) = app.entity_property_sections(i, handle, source, &Vec::new(), None, 0);
+        assert_eq!(title, "Line");
+    }
+}

src/app/record_api.rs

@@ -226,7 +226,11 @@ fn record(
     value
 }
 
-fn entity_record(entity: &codec::EntityType, reference_only: bool) -> Result<Value, String> {
+fn entity_record(
+    entity: &codec::EntityType,
+    reference_only: bool,
+    disabled_plugins: &rustc_hash::FxHashSet<String>,
+) -> Result<Value, String> {
     let (kind, properties) = enum_parts(entity)?;
     let mut value = record(
         "entities",
@@ -237,9 +241,18 @@ fn entity_record(entity: &codec::EntityType, reference_only: bool) -> Result<Val
         properties,
     );
     let object = value.as_object_mut().expect("record object");
+    // `display_type` carries the plugin-declared class label
+    // ("<Label> (<Native>)") while a live declaring plugin claims the
+    // entity's XDATA class identity; without one it is byte-identical to the
+    // native ui_name. The raw `type` and `record_type` fields stay native so
+    // existing scripts and filters keep working.
+    let native = crate::entities::names::ui_name(entity);
     object.insert(
         "display_type".into(),
-        json!(crate::entities::names::ui_name(entity)),
+        json!(crate::plugin::entity_labels::display_type_title(
+            crate::plugin::entity_labels::custom_entity_class_label(disabled_plugins, entity),
+            native.to_string(),
+        )),
     );
     object.insert(
         "record_type".into(),
@@ -308,12 +321,22 @@ fn map_records<T: Serialize>(
         .collect()
 }
 
-fn collection_records(scene: &crate::scene::Scene, collection: &str) -> Result<Vec<Value>, String> {
+fn collection_records(
+    scene: &crate::scene::Scene,
+    collection: &str,
+    disabled_plugins: &rustc_hash::FxHashSet<String>,
+) -> Result<Vec<Value>, String> {
     let document = &scene.document;
     match collection {
         "entities" => document
             .entities()
-            .map(|entity| entity_record(entity, scene.is_reference_only(entity.common().handle)))
+            .map(|entity| {
+                entity_record(
+                    entity,
+                    scene.is_reference_only(entity.common().handle),
+                    disabled_plugins,
+                )
+            })
             .collect(),
         "objects" => {
             let mut objects: Vec<_> = document.objects.iter().collect();
@@ -1387,28 +1410,32 @@ impl OpenCADStudio {
         }
         let definitions = referenced_definitions(&root_type);
         let runtime_schema = collection.and_then(|collection| {
-            collection_records(&self.tabs[self.active_tab].scene, collection)
-                .ok()?
-                .into_iter()
-                .find(|record| {
-                    let type_matches = record["type"]
-                        .as_str()
-                        .is_some_and(|name| name.eq_ignore_ascii_case(requested_type))
-                        || collection_root_type(collection)
-                            .is_some_and(|name| name.eq_ignore_ascii_case(requested_type));
-                    type_matches
-                        && request["handle"].as_str().is_none_or(|handle| {
-                            record["handle"].as_str().is_some_and(|actual| {
-                                actual.eq_ignore_ascii_case(without_hex_prefix(handle))
-                            })
+            collection_records(
+                &self.tabs[self.active_tab].scene,
+                collection,
+                &self.disabled_plugins,
+            )
+            .ok()?
+            .into_iter()
+            .find(|record| {
+                let type_matches = record["type"]
+                    .as_str()
+                    .is_some_and(|name| name.eq_ignore_ascii_case(requested_type))
+                    || collection_root_type(collection)
+                        .is_some_and(|name| name.eq_ignore_ascii_case(requested_type));
+                type_matches
+                    && request["handle"].as_str().is_none_or(|handle| {
+                        record["handle"].as_str().is_some_and(|actual| {
+                            actual.eq_ignore_ascii_case(without_hex_prefix(handle))
                         })
-                        && request["name"].as_str().is_none_or(|name| {
-                            record["name"]
-                                .as_str()
-                                .is_some_and(|actual| actual.eq_ignore_ascii_case(name))
-                        })
-                })
-                .map(|record| runtime_value_schema(&record["properties"], collection, ""))
+                    })
+                    && request["name"].as_str().is_none_or(|name| {
+                        record["name"]
+                            .as_str()
+                            .is_some_and(|actual| actual.eq_ignore_ascii_case(name))
+                    })
+            })
+            .map(|record| runtime_value_schema(&record["properties"], collection, ""))
         });
         json!({
             "ok":true,
@@ -1438,13 +1465,13 @@ impl OpenCADStudio {
         let mut records = Vec::new();
         if collection == "all" {
             for (name, _) in COLLECTIONS {
-                match collection_records(scene, name) {
+                match collection_records(scene, name, &self.disabled_plugins) {
                     Ok(mut values) => records.append(&mut values),
                     Err(error) => return failure("serialization_failed", error),
                 }
             }
         } else {
-            match collection_records(scene, collection) {
+            match collection_records(scene, collection, &self.disabled_plugins) {
                 Ok(values) => records = values,
                 Err(error) => return failure("unknown_collection", error),
             }
@@ -1766,6 +1793,36 @@ mod tests {
         assert_eq!(records["records"][0]["reference_only"], json!(false));
     }
 
+    #[test]
+    fn entities_records_display_type_stays_native_without_a_loaded_plugin() {
+        let mut app = OpenCADStudio::new_for_test();
+        app.automation_op(r#"{"op":"new"}"#);
+        let i = app.active_tab;
+
+        // An entity stamped with a perfect plugin class identity (registered
+        // app, class-prefix key) still shows the native display while no
+        // declaring plugin is loaded — the gating is live manager state.
+        let mut entity = EntityType::Line(codec::entities::Line::from_points(
+            Vector3::new(0.0, 0.0, 0.0),
+            Vector3::new(10.0, 0.0, 0.0),
+        ));
+        let mut record = codec::xdata::ExtendedDataRecord::new("CVIFC");
+        record.add_value(codec::xdata::XDataValue::String(
+            "CVIFC-CLASS:LINE".to_string(),
+        ));
+        entity.common_mut().extended_data.add_record(record);
+        app.tabs[i].scene.add_entity(entity);
+
+        let records = app.record_query(&json!({"collection":"entities"}));
+        assert_eq!(records["count"], 1);
+        assert_eq!(records["records"][0]["type"], json!("Line"));
+        assert_eq!(
+            records["records"][0]["display_type"],
+            json!("Line"),
+            "display_type is byte-identical to the native ui_name when no plugin is loaded"
+        );
+    }
+
     #[test]
     fn records_query_and_edit_every_mutable_record_family() {
         let mut app = OpenCADStudio::new_for_test();

src/plugin/entity_labels.rs

@@ -0,0 +1,302 @@
+// Plugin-declared entity class labels (API v10).
+//
+// A plugin that stamps stable class-identity keys into entity XDATA (one
+// string value per record, e.g. "CVIFC-CLASS:LINE") and declares an
+// `EntityClasses` table through `BuiltinPlugin::entity_classes` gets those
+// keys rendered as display labels while the plugin is loaded, e.g. the
+// Properties panel title becomes "Linear Element (Line)". The identity keys
+// round-trip the drawing; the labels never do — they are plugin-localizable
+// display text resolved from the live manager state at query time.
+//
+// Gating is structural, not incidental: declarations are only ever read
+// through the live plugin manager, so a plugin that is not installed,
+// disabled, cap-excluded (`OCS_PLUGIN_MAX_API_VERSION`), failed at load, has
+// been removed, or whose process has died contributes nothing — its entities
+// display as their bare native type. No snapshot of declarations is cached.
+
+use codec::EntityType;
+use rustc_hash::FxHashSet;
+
+// The wire declaration type and the resolution core exist only where the
+// out-of-process plugin runtime does; the web build has no plugins at all.
+#[cfg(not(target_arch = "wasm32"))]
+use codec::xdata::ExtendedData;
+#[cfg(not(target_arch = "wasm32"))]
+use ocs_plugin_api::ribbon::owned::OwnedEntityClasses;
+
+/// The display label a live, non-disabled plugin declares for `entity`'s
+/// XDATA class identity, or `None` for the native fallback.
+///
+/// Scans the entity's XDATA records for one whose application name is claimed
+/// by a live declaration and whose values carry a string starting with the
+/// declared class prefix; the remainder is the class key. "Unknown key,
+/// prefix-only, or empty label → `None`" is decided by whichever
+/// class-identity value is found first: a real marker with no resolvable label
+/// falls back to the native type rather than letting an unrelated record
+/// win. Foreign-app records and records without a class-identity value are
+/// skipped.
+pub(crate) fn custom_entity_class_label(
+    disabled: &FxHashSet<String>,
+    entity: &EntityType,
+) -> Option<String> {
+    let xdata = &entity.common().extended_data;
+    if xdata.records().is_empty() {
+        return None;
+    }
+    #[cfg(target_arch = "wasm32")]
+    {
+        // No external plugins exist in the web build; the native type stays.
+        let _ = disabled;
+        None
+    }
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        let declarations = crate::plugin::external::with_manager(|manager| {
+            manager.entity_class_declarations(|id| disabled.contains(id))
+        });
+        resolve_class_label(&declarations, xdata)
+    }
+}
+
+/// Pure resolution core over a set of live `(plugin id, declaration)` pairs,
+/// in load order. Kept separate from the live-manager plumbing so the
+/// semantics test without spawning plugin processes.
+#[cfg(not(target_arch = "wasm32"))]
+pub(crate) fn resolve_class_label(
+    declarations: &[(String, OwnedEntityClasses)],
+    xdata: &ExtendedData,
+) -> Option<String> {
+    use codec::xdata::XDataValue;
+
+    for record in xdata.records() {
+        let Some(declaration) = declaration_for(declarations, &record.application_name) else {
+            continue; // Foreign application — ignored.
+        };
+        for value in &record.values {
+            let XDataValue::String(text) = value else {
+                continue;
+            };
+            let Some(key) = text.strip_prefix(&declaration.class_prefix) else {
+                continue;
+            };
+            // First class-identity value decides; an empty remainder (prefix
+            // only), unknown key, or empty label all mean the native type.
+            if key.is_empty() {
+                return None;
+            }
+            return match declaration.labels.get(key) {
+                Some(label) if !label.is_empty() => Some(label.clone()),
+                _ => None,
+            };
+        }
+    }
+    None
+}
+
+/// The first declaration (load order) claiming `app_id`. Later duplicates are
+/// ignored and reported at debug level — an app id belongs to exactly one
+/// loaded plugin.
+#[cfg(not(target_arch = "wasm32"))]
+fn declaration_for<'a>(
+    declarations: &'a [(String, OwnedEntityClasses)],
+    app_id: &str,
+) -> Option<&'a OwnedEntityClasses> {
+    let mut found = None;
+    for (plugin_id, classes) in declarations {
+        if classes.app_id != app_id {
+            continue;
+        }
+        if found.is_some() {
+            log::debug!(
+                "[plugin] entity-class app id {app_id} is declared by more than one loaded \
+                 plugin; keeping the first declaration, ignoring plugin {plugin_id}"
+            );
+            continue;
+        }
+        found = Some(classes);
+    }
+    found
+}
+
+/// Display form: `"<Label> (<Native>)"` when a plugin class label matched,
+/// the native title unchanged otherwise. One rule for every surface — the
+/// Properties panel title (native = translated `ui_name_or_class`), the
+/// records API `display_type`, and the automation entity summary (native =
+/// `ui_name`).
+pub(crate) fn display_type_title(custom_label: Option<String>, native_title: String) -> String {
+    match custom_label {
+        Some(label) => format!("{label} ({native_title})"),
+        None => native_title,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use codec::entities::{Line, Point};
+    use codec::xdata::{ExtendedDataRecord, XDataValue};
+
+    use super::*;
+
+    fn declaration(plugin_id: &str, app_id: &str) -> (String, OwnedEntityClasses) {
+        (
+            plugin_id.to_string(),
+            OwnedEntityClasses {
+                app_id: app_id.to_string(),
+                class_prefix: "CVIFC-CLASS:".to_string(),
+                labels: [
+                    ("LINE".to_string(), "Linear Element".to_string()),
+                    (
+                        "CIRCULARARC".to_string(),
+                        "Circular Arc Element".to_string(),
+                    ),
+                ]
+                .into_iter()
+                .collect(),
+            },
+        )
+    }
+
+    fn line_with(tag: &str) -> EntityType {
+        let mut entity = EntityType::Line(Line::new());
+        let mut record = ExtendedDataRecord::new("CVIFC");
+        record.add_value(XDataValue::Integer32(1));
+        if !tag.is_empty() {
+            record.add_value(XDataValue::String(format!("CVIFC-CLASS:{tag}")));
+        }
+        entity.common_mut().extended_data.add_record(record);
+        entity
+    }
+
+    #[test]
+    fn declared_app_with_known_key_resolves_the_label() {
+        let entity = line_with("LINE");
+        let xdata = &entity.common().extended_data;
+        assert_eq!(
+            resolve_class_label(&[declaration("opencad.civil_ifc", "CVIFC")], xdata),
+            Some("Linear Element".to_string())
+        );
+    }
+
+    #[test]
+    fn foreign_app_records_are_ignored() {
+        let mut entity = EntityType::Point(Point::new());
+        let mut record = ExtendedDataRecord::new("SOMEONE-ELSE");
+        record.add_value(XDataValue::String("CVIFC-CLASS:LINE".to_string()));
+        entity.common_mut().extended_data.add_record(record);
+
+        assert_eq!(
+            resolve_class_label(
+                &[declaration("opencad.civil_ifc", "CVIFC")],
+                &entity.common().extended_data
+            ),
+            None,
+            "a record under a foreign app id must not resolve"
+        );
+    }
+
+    #[test]
+    fn record_without_identity_value_is_ignored_but_not_decisive() {
+        // First record: declared app, no class-identity value → skipped.
+        // Second record: declared app with a known key → resolves.
+        let mut entity = EntityType::Line(Line::new());
+        let mut markerless = ExtendedDataRecord::new("CVIFC");
+        markerless.add_value(XDataValue::Integer32(7));
+        entity.common_mut().extended_data.add_record(markerless);
+        let mut keyed = ExtendedDataRecord::new("CVIFC");
+        keyed.add_value(XDataValue::String("CVIFC-CLASS:LINE".to_string()));
+        entity.common_mut().extended_data.add_record(keyed);
+
+        assert_eq!(
+            resolve_class_label(
+                &[declaration("opencad.civil_ifc", "CVIFC")],
+                &entity.common().extended_data
+            ),
+            Some("Linear Element".to_string())
+        );
+
+        // And with no key anywhere: native fallback.
+        assert_eq!(
+            resolve_class_label(
+                &[declaration("opencad.civil_ifc", "CVIFC")],
+                &line_with("").common().extended_data
+            ),
+            None
+        );
+    }
+
+    #[test]
+    fn prefix_only_value_falls_back_to_native() {
+        let mut entity = EntityType::Line(Line::new());
+        let mut record = ExtendedDataRecord::new("CVIFC");
+        record.add_value(XDataValue::String("CVIFC-CLASS:".to_string()));
+        entity.common_mut().extended_data.add_record(record);
+
+        assert_eq!(
+            resolve_class_label(
+                &[declaration("opencad.civil_ifc", "CVIFC")],
+                &entity.common().extended_data
+            ),
+            None
+        );
+    }
+
+    #[test]
+    fn unknown_key_falls_back_to_native() {
+        let entity = line_with("TANGENT");
+        let xdata = &entity.common().extended_data;
+        assert_eq!(
+            resolve_class_label(&[declaration("opencad.civil_ifc", "CVIFC")], xdata),
+            None
+        );
+    }
+
+    #[test]
+    fn empty_label_falls_back_to_native() {
+        let mut empty_label = declaration("opencad.civil_ifc", "CVIFC");
+        empty_label
+            .1
+            .labels
+            .insert("LINE".to_string(), String::new());
+        let entity = line_with("LINE");
+        let xdata = &entity.common().extended_data;
+        assert_eq!(resolve_class_label(&[empty_label], xdata), None);
+    }
+
+    #[test]
+    fn later_duplicate_app_id_declaration_is_ignored() {
+        let mut second = declaration("other.plugin", "CVIFC");
+        second.1.labels.clear();
+        second
+            .1
+            .labels
+            .insert("LINE".to_string(), "Should Not Win".to_string());
+        let entity = line_with("LINE");
+        let xdata = &entity.common().extended_data;
+        assert_eq!(
+            resolve_class_label(&[declaration("opencad.civil_ifc", "CVIFC"), second], xdata),
+            Some("Linear Element".to_string()),
+            "the first loaded declaration for an app id wins"
+        );
+    }
+
+    #[test]
+    fn no_loaded_plugin_falls_back_to_native() {
+        // In the test build the live manager is empty (startup loading is
+        // compiled out), so the full path must yield the native fallback for
+        // an entity that carries a perfect identity record.
+        let entity = line_with("LINE");
+        assert_eq!(
+            custom_entity_class_label(&FxHashSet::default(), &entity),
+            None
+        );
+    }
+
+    #[test]
+    fn display_title_qualifies_native_with_label() {
+        assert_eq!(
+            display_type_title(Some("Linear Element".to_string()), "Line".to_string()),
+            "Linear Element (Line)"
+        );
+        assert_eq!(display_type_title(None, "Line".to_string()), "Line");
+    }
+}

src/plugin/mod.rs

@@ -2,6 +2,7 @@
 // from the application bundle or user plugins folder (see `external`).
 // See `docs/plugin-architecture.md`.
 
+pub mod entity_labels;
 pub mod external;
 pub mod host;
 pub mod marketplace;