feat(system): log-health scanner + Add/Edit-Printer setup pre-flight

Adds a passive log-health check that complements the active Connection
  Diagnostic. Scans Bambuddy's recent app log against a curated allowlist
  catalog of known failure signatures (rejected access code, FTPS :990
  timeout, FTPS TLS failure, flapping MQTT, unreachable camera, SQLite
  "database is locked" contention), dedupes and classifies each finding
  as layer8/environment/bug, and deep-links to the troubleshooting wiki.
  Sample log lines are sanitized before they leave the process. Exposed
  via GET /system/health and surfaced on two surfaces sharing one
  SystemHealthPanel component: a System Health section on the System
  page, and inline in the bug reporter when the form opens.

  The Add-Printer and Edit-Printer dialogs gained a setup-time pre-flight:
  saving runs the connection diagnostic and, on a failed check, warns with
  a "save anyway" escape hatch instead of silently saving a printer that
  will immediately show offline.

  Log read/parse/sanitize primitives extracted from routes/support.py into
  a shared services/log_reader.py (behaviour-preserving); affected support
  tests repointed accordingly.

  Tests: test_log_health.py (11), test_system_api.py (2 new),
  SystemHealthPanel + BugReportBubble + AddPrinterPreflight +
  EditPrinterPreflight (8 frontend). All strings translated across the 9
  locales. Backend ruff clean, full unit suite green, frontend build +
  eslint clean, i18n parity green.

frontend/src/components/BugReportBubble.tsx

@@ -4,6 +4,7 @@ import { useTranslation } from 'react-i18next';
 import { useQuery } from '@tanstack/react-query';
 import { api, bugReportApi, type PrinterDiagnosticResult } from '../api/client';
 import { DiagnosticChecklist } from './ConnectionDiagnostic';
+import { SystemHealthPanel } from './SystemHealthPanel';
 import { Collapsible } from './Collapsible';
 
 type ViewState = 'form' | 'logging' | 'stopping' | 'submitting' | 'success' | 'error';
@@ -85,6 +86,18 @@ export function BugReportBubble() {
   const diagnosticEntries = diagnosticScan.data ?? [];
   const diagnosticProblems = diagnosticEntries.filter((e) => e.result.overall === 'problems');
 
+  // Scan recent logs against the known-issue catalog. Like the diagnostic
+  // above, this surfaces user-fixable ("layer 8") problems before a report is
+  // filed. Only shown when something matched — a clean scan stays silent so
+  // the form is uncluttered.
+  const logHealthScan = useQuery({
+    queryKey: ['bugReportLogHealth'],
+    enabled: isOpen && viewState === 'form',
+    staleTime: 30_000,
+    queryFn: api.getSystemHealth,
+  });
+  const logFindings = logHealthScan.data?.findings ?? [];
+
   // Elapsed timer for logging phase — auto-stop at 5 minutes
   useEffect(() => {
     if (viewState !== 'logging') return;
@@ -299,6 +312,25 @@ export function BugReportBubble() {
                       </div>
                     )}
 
+                  {/* Log-health scan — known issues found in recent logs.
+                      Shown only when something matched. */}
+                  {!logHealthScan.isLoading && logFindings.length > 0 && logHealthScan.data && (
+                    <div className="rounded-lg bg-amber-50 dark:bg-amber-900/20 border border-amber-200 dark:border-amber-800 p-3 space-y-3">
+                      <div className="flex items-start gap-2">
+                        <Stethoscope className="w-4 h-4 mt-0.5 flex-shrink-0 text-amber-600 dark:text-amber-400" />
+                        <div>
+                          <p className="text-sm font-medium text-amber-700 dark:text-amber-300">
+                            {t('bugReport.logHealthSummary')}
+                          </p>
+                          <p className="text-xs text-amber-800 dark:text-amber-200 mt-0.5">
+                            {t('bugReport.logHealthIntro')}
+                          </p>
+                        </div>
+                      </div>
+                      <SystemHealthPanel result={logHealthScan.data} />
+                    </div>
+                  )}
+
                   {/* Description */}
                   <div>
                     <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">

frontend/src/components/SystemHealthPanel.tsx

@@ -0,0 +1,107 @@
+import type { ElementType } from 'react';
+import { useTranslation } from 'react-i18next';
+import { XCircle, AlertTriangle, CheckCircle2, ExternalLink, Wrench, ServerCog, Bug } from 'lucide-react';
+import type { LogFinding, LogFindingCategory, SystemHealthResult } from '../api/client';
+
+const WIKI_TROUBLESHOOTING = 'https://wiki.bambuddy.cool/reference/troubleshooting/';
+
+const CATEGORY_META: Record<LogFindingCategory, { icon: ElementType; badgeClass: string }> = {
+  layer8: { icon: Wrench, badgeClass: 'bg-bambu-green/15 text-bambu-green border-bambu-green/30' },
+  environment: { icon: ServerCog, badgeClass: 'bg-amber-500/15 text-amber-300 border-amber-500/30' },
+  bug: { icon: Bug, badgeClass: 'bg-red-500/15 text-red-300 border-red-500/30' },
+};
+
+/**
+ * One detected log-health finding. Cause/fix/name text is rendered from i18n
+ * keyed by signature_id; an unknown signature (frontend older than backend)
+ * still renders gracefully via the defaultValue fallbacks.
+ */
+function FindingCard({ finding }: { finding: LogFinding }) {
+  const { t } = useTranslation();
+  const id = finding.signature_id;
+  const name = t(`systemHealth.signature.${id}.name`, { defaultValue: id });
+  const cause = t(`systemHealth.signature.${id}.cause`, { defaultValue: '' });
+  const fix = t(`systemHealth.signature.${id}.fix`, { defaultValue: '' });
+  const meta = CATEGORY_META[finding.category] ?? CATEGORY_META.bug;
+  const CategoryIcon = meta.icon;
+  const SeverityIcon = finding.severity === 'error' ? XCircle : AlertTriangle;
+  const severityColor = finding.severity === 'error' ? 'text-red-400' : 'text-amber-400';
+
+  return (
+    <div className="bg-bambu-dark rounded-lg border border-bambu-dark-tertiary p-4 space-y-2">
+      <div className="flex items-start gap-3">
+        <SeverityIcon className={`w-5 h-5 flex-shrink-0 mt-0.5 ${severityColor}`} />
+        <div className="flex-1 min-w-0">
+          <div className="flex items-center gap-2 flex-wrap">
+            <span className="text-sm font-medium text-white">{name}</span>
+            <span
+              className={`inline-flex items-center gap-1 text-xs px-2 py-0.5 rounded-full border ${meta.badgeClass}`}
+            >
+              <CategoryIcon className="w-3 h-3" />
+              {t(`systemHealth.category.${finding.category}`)}
+            </span>
+          </div>
+          {cause && <p className="text-xs text-bambu-gray mt-1">{cause}</p>}
+        </div>
+      </div>
+
+      {fix && (
+        <div className="text-xs text-white/90 bg-bambu-dark-secondary rounded px-3 py-2">
+          <span className="text-bambu-green font-medium">{t('systemHealth.fixLabel')}</span> {fix}
+        </div>
+      )}
+
+      <div className="text-xs font-mono text-bambu-gray/70 bg-bambu-dark-secondary rounded px-3 py-2 break-all">
+        {finding.sample}
+      </div>
+
+      <div className="flex items-center justify-between gap-2 flex-wrap">
+        <span className="text-xs text-bambu-gray">
+          {t('systemHealth.occurrences', { times: finding.count, lastSeen: finding.last_seen })}
+        </span>
+        <a
+          href={`${WIKI_TROUBLESHOOTING}#${finding.wiki_anchor}`}
+          target="_blank"
+          rel="noopener noreferrer"
+          className="inline-flex items-center gap-1 text-xs text-bambu-green hover:underline"
+        >
+          {t('systemHealth.learnMore')}
+          <ExternalLink className="w-3 h-3" />
+        </a>
+      </div>
+    </div>
+  );
+}
+
+/**
+ * Presentational panel for a log-health scan result. Shared by the System page
+ * section and the bug-report bubble so both surfaces look identical.
+ */
+export function SystemHealthPanel({ result }: { result: SystemHealthResult }) {
+  const { t } = useTranslation();
+
+  if (!result.log_available) {
+    return (
+      <div className="rounded-lg bg-amber-500/10 border border-amber-500/30 px-4 py-3 text-sm text-amber-300">
+        {t('systemHealth.logUnavailable')}
+      </div>
+    );
+  }
+
+  if (result.findings.length === 0) {
+    return (
+      <div className="rounded-lg bg-bambu-green/10 border border-bambu-green/30 px-4 py-3 text-sm text-bambu-green flex items-center gap-2">
+        <CheckCircle2 className="w-5 h-5 flex-shrink-0" />
+        <span>{t('systemHealth.clean', { times: result.scanned_entries })}</span>
+      </div>
+    );
+  }
+
+  return (
+    <div className="space-y-3">
+      {result.findings.map((finding) => (
+        <FindingCard key={finding.signature_id} finding={finding} />
+      ))}
+    </div>
+  );
+}