fix: Filter out english if over confidence threshold

English has a tendency of sneaking into the language feeds. If english
is not one of the target languages check if english confidence threshold
is high enough that we aught to filter it out.

firehose/firehose.go

@@ -440,20 +440,28 @@ type PostProcessor struct {
 
 // Rename to DetectLanguage since it's no longer Norwegian-specific
 func (p *PostProcessor) DetectLanguage(text string, currentLangs []string, targetLangs []lingua.Language) (bool, []string) {
+	// First check English confidence separately
+	englishConf := p.languageDetector.ComputeLanguageConfidence(text, lingua.English)
+
+	// If text is primarily English (high confidence), skip it unless English is a target language
+	if englishConf > 0.8 && !lo.Contains(targetLangs, lingua.English) {
+		return false, currentLangs
+	}
+
 	var highestConf float64
 	var detectedLang lingua.Language
 
-	// Check confidence for English and all target languages
-	for _, lang := range append([]lingua.Language{lingua.English}, targetLangs...) {
+	// Only check target languages
+	for _, lang := range targetLangs {
 		conf := p.languageDetector.ComputeLanguageConfidence(text, lang)
 		if conf > highestConf {
 			highestConf = conf
 			detectedLang = lang
 		}
 	}
 
-	// If confidence is too low or detected language is English, skip
-	if highestConf < p.config.ConfidenceThreshold || detectedLang == lingua.English {
+	// If confidence is too low, skip
+	if highestConf < p.config.ConfidenceThreshold {
 		return false, currentLangs
 	}