feat: surface BMC collection errors in parse-errors panel and event log

When Inspur component.log sections return {"error":"...","code":N} instead
of hardware data, the parser now:
- stores them in AnalysisResult.CollectionErrors (new model field)
- mirrors each one into result.Events with Source="BMC/<section>"
  so the chart viewer event table shows the specific BMC module
- feeds them into /api/parse-errors as bmc_collection_error entries

UI adds a collapsible "Collection diagnostics" panel below the chart
iframe (outside /chart) that appears when /api/parse-errors returns
any items; resets on data clear.

Affected sections in this dump: HDD (1458), PCIe Devices (1458),
Network Adapters (1458), Disk Backplane.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/server/handlers.go

@@ -854,6 +854,28 @@ func (s *Server) handleGetParseErrors(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	// BMC-reported collection failures surfaced by vendor parsers.
+	if result != nil {
+		for _, ce := range result.CollectionErrors {
+			msg := strings.TrimSpace(ce.Message)
+			if msg == "" {
+				continue
+			}
+			detail := ""
+			if ce.Code != 0 {
+				detail = fmt.Sprintf("code %d", ce.Code)
+			}
+			add(parseErrorEntry{
+				Source:   "bmc",
+				Category: "bmc_collection_error",
+				Severity: "warning",
+				Path:     ce.Section,
+				Message:  msg,
+				Detail:   detail,
+			})
+		}
+	}
+
 	sort.Slice(items, func(i, j int) bool {
 		if items[i].Severity != items[j].Severity {
 			// error > warning > info