perf(logviewer): 512 KB tail instead of 1 MB

1 MB (~6500 lines) fetched, split and re-rendered every second made the window
lag. 512 KB (~3200 lines) keeps a useful backlog — double the original 256 KB —
while staying responsive.

frontend/src/components/LogViewer.tsx

@@ -21,12 +21,13 @@ import { TailLogFile, GetLogFilePath } from '../../wailsjs/go/main/App';
 //     256 KB blob: with "cluster" or "acom" typed in, the window becomes exactly
 //     the subsystem trace you would have grepped for.
 //   • It polls only while open. A closed dialog costs nothing.
-// 1 MB ≈ 6500 lines. The window is a sliding tail: once new lines push past it
+// 512 KB ≈ 3200 lines. The window is a sliding tail: once new lines push past it
 // the oldest fall out of the fetched text entirely, so a small buffer dropped
 // lines the operator was still reading during a busy trace (CAT/cluster/antenna
-// polling). The backend caps this at 4 MB; 1 MB is a good balance against the
-// per-poll payload while open.
-const TAIL_BYTES = 1024 * 1024;
+// polling). This is double the old 256 KB — 1 MB was tried but the per-second
+// fetch + split + re-render of ~6500 lines made the window lag. 512 KB keeps a
+// useful backlog while staying smooth. The backend caps this at 4 MB.
+const TAIL_BYTES = 512 * 1024;
 const POLL_MS = 1000;
 
 export function LogViewer({ open, onOpenChange }: { open: boolean; onOpenChange: (v: boolean) => void }) {