fix: truncate long error text in fleet prune estimate per-node rows (#1802)

Unreachable nodes rendered their error string in a shrink-0 span with no
width bound, so a verbose daemon or proxy error pushed the row past the
card edge. Bound the error span to 55% and ellipsize, matching the
existing pattern in the label-and-stop card; the full message stays
available via the row title tooltip.

frontend/src/components/fleet/FleetActions/cards/FleetPruneCard.test.tsx

@@ -126,6 +126,31 @@ it('shows 0 reclaimable · partial when successful targets report zero bytes', a
   expect(screen.getByText('PART')).toBeInTheDocument();
 });
 
+it('truncates a long unreachable error without clipping reachable byte counts', async () => {
+  const longError = `Pilot tunnel is disconnected: ${'x'.repeat(400)}`;
+  const twoNodes = [...nodes, { id: 2, name: 'edge', status: 'offline' }] as unknown as FleetNode[];
+  mockedFetch.mockImplementation((url: string) => {
+    if (url === '/fleet/prune/estimate') {
+      return Promise.resolve(jsonResponse(200, {
+        totalBytes: 4096,
+        perNode: [
+          { nodeId: 1, nodeName: 'central', reclaimableBytes: 4096, reachable: true },
+          { nodeId: 2, nodeName: 'edge', reclaimableBytes: 0, reachable: false, error: longError },
+        ],
+      }));
+    }
+    return Promise.resolve(jsonResponse(404, {}));
+  });
+
+  render(<FleetPruneCard nodes={twoNodes} />);
+  const errorSpan = await screen.findByText(longError);
+  expect(errorSpan.className).toContain('truncate');
+  expect(errorSpan.className).toContain('max-w-[55%]');
+  expect(screen.getByTitle(longError)).toBeInTheDocument();
+  const byteSpan = screen.getByText('4 KB');
+  expect(byteSpan.className).not.toContain('truncate');
+});
+
 it('drops the unlock footer once dry run review is valid', async () => {
   const user = userEvent.setup();
   mockedFetch.mockImplementation((url: string) => {

frontend/src/components/fleet/FleetActions/cards/FleetPruneCard.tsx

@@ -416,7 +416,7 @@ function EstimateSection({ estimate }: { estimate: EstimateState }) {
                 {node.reachable ? (node.partial ? 'PART' : 'OK') : '--'}
               </span>
               <span className="min-w-0 flex-1 truncate font-mono text-[11px] text-stat-value">{node.nodeName}</span>
-              <span className={cn(KICKER, 'shrink-0 tabular-nums', node.reachable ? 'text-stat-subtitle' : 'text-stat-icon')}>
+              <span className={cn(KICKER, 'shrink-0 tabular-nums', node.reachable ? 'text-stat-subtitle' : 'max-w-[55%] truncate text-stat-icon')}>
                 {node.reachable ? formatBytes(node.reclaimableBytes) : (node.error ?? 'unreachable')}
               </span>
             </li>