fix: add readFileDeduplication to webview-ui test

- Update ExtensionStateContext test to include the new experiment flag
- This ensures TypeScript types match the expected experiment structure

Author: hannesrudolph

webview-ui/src/context/__tests__/ExtensionStateContext.spec.tsx

@@ -226,6 +226,7 @@ describe("mergeExtensionState", () => {
 				disableCompletionCommand: false,
 				concurrentFileReads: true,
 				multiFileApplyDiff: true,
+				readFileDeduplication: false,
 			} as Record<ExperimentId, boolean>,
 		}
 
@@ -242,6 +243,7 @@ describe("mergeExtensionState", () => {
 			disableCompletionCommand: false,
 			concurrentFileReads: true,
 			multiFileApplyDiff: true,
+			readFileDeduplication: false,
 		})
 	})
 })