fix(perf): review findings in the service and the panel

- The panel loads only while open. Its models are fresh arrays every
  sample, so a hidden instance rebuilt its rows every 2s for the whole
  session.
- The public IP fetch never kills one already running, and waits 30
  minutes from the last attempt, not the last success: a rate-limited
  or offline fetch was retried every minute.
- curl -4, so an IPv6 answer cannot silently stall the VPN check.
- CPU load sums only the first eight /proc/stat fields. guest and
  guest_nice are already inside user and nice, and counting them again
  read high while VMs ran.
- df gets timeout -k; the VRAM scan is not restarted over itself.
- The GPU name joins the host constants in Perf.qml.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/desktop/island/perf/test_perf.js b/desktop/island/perf/test_perf.js
index c336cf0..5f39f5d 100644
--- a/desktop/island/perf/test_perf.js
+++ b/desktop/island/perf/test_perf.js
@@ -35,6 +35,8 @@ assert.strictEqual(t.length, 3);
 assert.deepStrictEqual(t[0], { total: 1000, idle: 850 });
 assert.deepStrictEqual(t[1], { total: 500, idle: 425 });
 assert.deepStrictEqual(P.cpuTimes(""), []);
+// guest and guest_nice are already inside user and nice: not added twice.
+assert.deepStrictEqual(P.cpuTimes("cpu  100 0 0 100 0 0 0 0 80 0"), [{ total: 200, idle: 100 }]);
 
 // load: busy share of the delta; no prev, or no time passed, is null.
 assert.strictEqual(P.load({ total: 1000, idle: 850 }, { total: 1100, idle: 925 }), 25);