Add rspamd symbol descriptions from embedded/API lookup

Embed rspamd-symbols.json in the binary to provide human-readable
descriptions for rspamd symbols in reports. Optionally fetch fresh
symbols from a configurable rspamd API URL (--rspamd-api-url flag),
falling back to the embedded list on error. Update the frontend to
display descriptions alongside symbol names and scores.

pkg/analyzer/rspamd.go

@@ -37,11 +37,13 @@ const (
 )
 
 // RspamdAnalyzer analyzes rspamd results from email headers
-type RspamdAnalyzer struct{}
+type RspamdAnalyzer struct {
+	symbols map[string]string
+}
 
-// NewRspamdAnalyzer creates a new rspamd analyzer
-func NewRspamdAnalyzer() *RspamdAnalyzer {
-	return &RspamdAnalyzer{}
+// NewRspamdAnalyzer creates a new rspamd analyzer with optional symbol descriptions
+func NewRspamdAnalyzer(symbols map[string]string) *RspamdAnalyzer {
+	return &RspamdAnalyzer{symbols: symbols}
 }
 
 // AnalyzeRspamd extracts and analyzes rspamd results from email headers
@@ -83,6 +85,16 @@ func (a *RspamdAnalyzer) AnalyzeRspamd(email *EmailMessage) *api.RspamdResult {
 		result.Server = &server
 	}
 
+	// Populate symbol descriptions from the lookup map
+	if a.symbols != nil {
+		for name, sym := range result.Symbols {
+			if desc, ok := a.symbols[name]; ok {
+				sym.Description = &desc
+				result.Symbols[name] = sym
+			}
+		}
+	}
+
 	// Derive IsSpam from score vs reject threshold.
 	if result.Threshold > 0 {
 		result.IsSpam = result.Score >= result.Threshold