change(web): improve split input-segment source merge code

Author: jahorton

web/src/engine/predictive-text/worker-thread/src/main/correction/search-quotient-spur.ts

@@ -359,6 +359,12 @@ export abstract class SearchQuotientSpur implements SearchQuotientNode {
     if(this.inputSource) {
       const inputId = this.inputSource.segment.transitionId;
       if(inputId && parentSources.length > 0 && parentSources[parentSources.length - 1].segment.transitionId == inputId) {
+        // Fuse the input sources!
+        const tailSrc = parentSources[parentSources.length - 1];
+        tailSrc.segment.end = this.inputSource.segment.end;
+        if(tailSrc.segment.end) {
+          delete tailSrc.segment.end;
+        }
         return parentSources;
       }