feat(m8): event-based alerts — Xid/OOM/MCE/PCIe/disk from the kernel log — 0.34.0

AlertMonitor now scans the kernel log (journalctl -k) every ~30s and fires
one-shot, cooldown-gated desktop alerts on critical events: NVIDIA Xid, OOM
kills, CPU machine-checks, PCIe AER, and disk I/O errors — so users are warned
the moment something goes wrong, not only on a temperature threshold. Disk I/O
errors come from the kernel log (no root needed, unlike smartctl). Edge/spam
protection reuses the existing cooldown model. syslogs.scan_critical() does the
matching; init seeds last-scan to "now" so old boot logs don't alert on launch.
Tests for the matcher + monitor gating/cooldown; Settings note updated.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/test_syslogs.py

@@ -72,6 +72,25 @@ class DisplayTests(unittest.TestCase):
         self.assertTrue(any(a.startswith("_COMM=") for a in cmd))
 
 
+class ScanCriticalTests(unittest.TestCase):
+    def test_matches_each_category(self):
+        text = "\n".join([
+            "NVRM: Xid (PCI:0000:01:00): 79, GPU has fallen off the bus",
+            "Out of memory: Killed process 1234 (PathOfExile)",
+            "mce: [Hardware Error]: CPU 0",
+            "pcieport 0000:00:01.0: AER: Corrected error received",
+            "blk_update_request: I/O error, dev sda, sector 99",
+            "this is a perfectly normal line",
+        ])
+        labels = {label for label, _ in syslogs.scan_critical(text)}
+        self.assertEqual(labels, {
+            "GPU error (Xid)", "Out of memory", "CPU machine-check",
+            "PCIe error", "Disk I/O error"})
+
+    def test_clean_log_no_events(self):
+        self.assertEqual(syslogs.scan_critical("usb 1-2: new high-speed device\nsystemd: started"), [])
+
+
 class CollectTests(unittest.TestCase):
     def test_collect_combines_sections(self):
         with mock.patch.object(syslogs, "kernel_log", return_value="NVRM: Xid 79"), \