add llm adapter interface and implementations

internal/llm/llm.go

@@ -0,0 +1,42 @@
+package llm
+
+import (
+	"context"
+	"fmt"
+)
+
+// Adapter interface for LLM text processing
+type Adapter interface {
+	Process(ctx context.Context, text string) (string, error)
+}
+
+// Config holds LLM adapter configuration
+type Config struct {
+	Provider          string
+	APIKey            string
+	Model             string
+	RemoveStutters    bool
+	AddPunctuation    bool
+	FixGrammar        bool
+	RemoveFillerWords bool
+	CustomPrompt      string
+	Keywords          []string
+}
+
+// NewAdapter creates an LLM adapter based on the provider
+func NewAdapter(cfg Config) (Adapter, error) {
+	switch cfg.Provider {
+	case "openai":
+		if cfg.APIKey == "" {
+			return nil, fmt.Errorf("OpenAI API key required")
+		}
+		return NewOpenAIAdapter(cfg), nil
+	case "groq":
+		if cfg.APIKey == "" {
+			return nil, fmt.Errorf("Groq API key required")
+		}
+		return NewGroqAdapter(cfg), nil
+	default:
+		return nil, fmt.Errorf("unsupported LLM provider: %s", cfg.Provider)
+	}
+}