fix(combobox-web): address review comments

- Split "loading or unavailable" test cases into separate loading and
  unavailable variants to make coverage explicit
- Add changelog entry for the attribute-presence bug that bypassed
  custom editability conditions

Author: r0b1n

packages/pluggableWidgets/combobox-web/CHANGELOG.md

@@ -12,6 +12,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 - We fixed an issue where the editability setting was inverted: setting editability to `false` allowed editing, and setting it to `true` prevented editing.
 
+- We fixed an issue where the custom editability condition (`never` or `conditionally`) was ignored when the combobox attribute was present and editable.
+
 ## [2.8.1] - 2026-04-30
 
 ### Fixed

packages/pluggableWidgets/combobox-web/src/helpers/Database/__tests__/utils.spec.ts

@@ -91,7 +91,7 @@ describe("getReadonly", () => {
             expect(result).toBe(false);
         });
 
-        it("is read-only when customEditability is 'conditionally' and expression value is undefined (loading or unavailable)", () => {
+        it("is read-only when customEditability is 'conditionally' and expression is loading", () => {
             const targetAttribute = new EditableValueBuilder<string>().withValue("value").build();
 
             const result = getReadonly(
@@ -102,6 +102,18 @@ describe("getReadonly", () => {
 
             expect(result).toBe(true);
         });
+
+        it("is read-only when customEditability is 'conditionally' and expression is unavailable", () => {
+            const targetAttribute = new EditableValueBuilder<string>().withValue("value").build();
+
+            const result = getReadonly(
+                targetAttribute as unknown as EditableValue<string | Big>,
+                "conditionally",
+                dynamic.unavailable()
+            );
+
+            expect(result).toBe(true);
+        });
     });
 
     describe("when targetAttribute is undefined", () => {
@@ -129,10 +141,16 @@ describe("getReadonly", () => {
             expect(result).toBe(false);
         });
 
-        it("is read-only when customEditability is 'conditionally' and expression value is undefined (loading or unavailable)", () => {
+        it("is read-only when customEditability is 'conditionally' and expression is loading", () => {
             const result = getReadonly(undefined, "conditionally", dynamic.loading());
 
             expect(result).toBe(true);
         });
+
+        it("is read-only when customEditability is 'conditionally' and expression is unavailable", () => {
+            const result = getReadonly(undefined, "conditionally", dynamic.unavailable());
+
+            expect(result).toBe(true);
+        });
     });
 });