feat: add manual summarizer latency probe for admin system view

JobTrackerApi/Controllers/AdminSystemController.cs

@@ -40,6 +40,13 @@ public sealed class AdminSystemController : ControllerBase
         SummarizerMetrics Summarizer
     );
 
+    [HttpPost("summarizer/probe")]
+    public async Task<IActionResult> RunSummarizerProbe(CancellationToken cancellationToken)
+    {
+        await _summarizer.RunProbeAsync(cancellationToken);
+        return NoContent();
+    }
+
     [HttpGet]
     public async Task<ActionResult<SystemStatusDto>> Get(CancellationToken cancellationToken)
     {

job-tracker-ui/src/pages/AdminSystemPage.tsx

@@ -84,10 +84,30 @@ export default function AdminSystemPage() {
           <Typography variant="h5" sx={{ fontWeight: 950 }}>System status</Typography>
           <Typography sx={{ color: "text.secondary" }}>Quick operational view of storage, email, and summarizer health.</Typography>
         </Box>
+        <Box sx={{ display: "flex", gap: 1, flexWrap: "wrap" }}>
+          <Button
+            variant="outlined"
+            onClick={async () => {
+              setRunningProbe(true);
+              setError(null);
+              try {
+                await api.post("/admin/system/summarizer/probe");
+                await load();
+              } catch (e: any) {
+                setError(e?.response?.data || e?.message || "Failed to run summarizer probe.");
+              } finally {
+                setRunningProbe(false);
+              }
+            }}
+            disabled={loading || runningProbe}
+          >
+            {runningProbe ? "Running probe..." : "Run probe now"}
+          </Button>
           <Button variant="contained" onClick={() => void load()} disabled={loading}>
             {loading ? "Refreshing..." : "Refresh"}
           </Button>
         </Box>
+      </Box>
 
       {error ? <Alert severity="error">{error}</Alert> : null}