feat: display last run time for each build in UI (#373)

Add updatedAt field to Build interface and show "Last run" timestamp
in both BuildList and BuildDetails components.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: okstryzhak

src/components/BuildDetails.tsx

@@ -57,6 +57,13 @@ const BuildDetails: React.FunctionComponent = () => {
                 {formatDateTime(selectedBuild.createdAt)}
               </Typography>
             </Grid>
+            {selectedBuild.updatedAt && (
+              <Grid item>
+                <Typography variant="caption" color="textSecondary">
+                  Last run: {formatDateTime(selectedBuild.updatedAt)}
+                </Typography>
+              </Grid>
+            )}
           </Grid>
         </Box>
       </Grid>

src/components/BuildList/index.tsx

@@ -153,6 +153,13 @@ const BuildList: FunctionComponent = () => {
                             {formatDateTime(build.createdAt)}
                           </Typography>
                         </Grid>
+                        {build.updatedAt && (
+                          <Grid item>
+                            <Typography variant="caption" color="textSecondary">
+                              Last run: {formatDateTime(build.updatedAt)}
+                            </Typography>
+                          </Grid>
+                        )}
                         <Grid item>
                           <Grid container justifyContent="space-between">
                             <Grid item>

src/types/build.ts

@@ -10,6 +10,7 @@ export interface Build {
   branchName: string;
   status: BuildStatus;
   createdAt: string;
+  updatedAt: string;
   createdBy: string;
   testRuns: TestRun[];