feat: add provider interface and registry

internal/provider/groq.go

@@ -0,0 +1,42 @@
+package provider
+
+import "strings"
+
+// GroqProvider implements Provider for Groq services
+type GroqProvider struct{}
+
+func (p *GroqProvider) Name() string {
+	return "groq"
+}
+
+func (p *GroqProvider) RequiresAPIKey() bool {
+	return true
+}
+
+func (p *GroqProvider) ValidateAPIKey(key string) bool {
+	return strings.HasPrefix(key, "gsk_")
+}
+
+func (p *GroqProvider) SupportsTranscription() bool {
+	return true
+}
+
+func (p *GroqProvider) SupportsLLM() bool {
+	return true
+}
+
+func (p *GroqProvider) DefaultTranscriptionModel() string {
+	return "whisper-large-v3-turbo"
+}
+
+func (p *GroqProvider) DefaultLLMModel() string {
+	return "llama-3.3-70b-versatile"
+}
+
+func (p *GroqProvider) TranscriptionModels() []string {
+	return []string{"whisper-large-v3", "whisper-large-v3-turbo"}
+}
+
+func (p *GroqProvider) LLMModels() []string {
+	return []string{"llama-3.3-70b-versatile", "llama-3.1-8b-instant", "mixtral-8x7b-32768"}
+}