refactor provider interface to return models with metadata

- replaced old TranscriptionModels/LLMModels/SupportsX methods with Models() []Model
- added DefaultModel(t ModelType), IsLocal() to interface
- added helpers: GetModel, ModelsOfType, FindModelByID, ModelsForLanguage, ValidateModelLanguage
- all providers now return full Model metadata with SupportedLanguages, AdapterType, Endpoint
- groq distil-whisper-large-v3-en marked as english-only
- updated TUI to use new interface

internal/provider/openai.go

@@ -1,6 +1,10 @@
 package provider
 
-import "strings"
+import (
+	"strings"
+
+	"github.com/leonardotrapani/hyprvoice/internal/language"
+)
 
 // OpenAIProvider implements Provider for OpenAI services
 type OpenAIProvider struct{}
@@ -17,26 +21,80 @@ func (p *OpenAIProvider) ValidateAPIKey(key string) bool {
 	return strings.HasPrefix(key, "sk-")
 }
 
-func (p *OpenAIProvider) SupportsTranscription() bool {
-	return true
+func (p *OpenAIProvider) IsLocal() bool {
+	return false
 }
 
-func (p *OpenAIProvider) SupportsLLM() bool {
-	return true
+func (p *OpenAIProvider) Models() []Model {
+	allLangs := language.AllLanguageCodes()
+
+	return []Model{
+		// transcription models
+		{
+			ID:                 "whisper-1",
+			Name:               "Whisper 1",
+			Description:        "OpenAI's production speech-to-text model",
+			Type:               Transcription,
+			Streaming:          false,
+			Local:              false,
+			AdapterType:        "openai",
+			SupportedLanguages: allLangs,
+			Endpoint:           &EndpointConfig{BaseURL: "https://api.openai.com", Path: "/v1/audio/transcriptions"},
+		},
+		// LLM models
+		{
+			ID:                 "gpt-4o-mini",
+			Name:               "GPT-4o Mini",
+			Description:        "Fast and affordable GPT-4 variant",
+			Type:               LLM,
+			Streaming:          false,
+			Local:              false,
+			AdapterType:        "openai",
+			SupportedLanguages: allLangs,
+			Endpoint:           &EndpointConfig{BaseURL: "https://api.openai.com", Path: "/v1/chat/completions"},
+		},
+		{
+			ID:                 "gpt-4o",
+			Name:               "GPT-4o",
+			Description:        "Most capable GPT-4 model",
+			Type:               LLM,
+			Streaming:          false,
+			Local:              false,
+			AdapterType:        "openai",
+			SupportedLanguages: allLangs,
+			Endpoint:           &EndpointConfig{BaseURL: "https://api.openai.com", Path: "/v1/chat/completions"},
+		},
+		{
+			ID:                 "gpt-4-turbo",
+			Name:               "GPT-4 Turbo",
+			Description:        "Faster GPT-4 with large context window",
+			Type:               LLM,
+			Streaming:          false,
+			Local:              false,
+			AdapterType:        "openai",
+			SupportedLanguages: allLangs,
+			Endpoint:           &EndpointConfig{BaseURL: "https://api.openai.com", Path: "/v1/chat/completions"},
+		},
+		{
+			ID:                 "gpt-3.5-turbo",
+			Name:               "GPT-3.5 Turbo",
+			Description:        "Fast and cost-effective",
+			Type:               LLM,
+			Streaming:          false,
+			Local:              false,
+			AdapterType:        "openai",
+			SupportedLanguages: allLangs,
+			Endpoint:           &EndpointConfig{BaseURL: "https://api.openai.com", Path: "/v1/chat/completions"},
+		},
+	}
 }
 
-func (p *OpenAIProvider) DefaultTranscriptionModel() string {
-	return "whisper-1"
-}
-
-func (p *OpenAIProvider) DefaultLLMModel() string {
-	return "gpt-4o-mini"
-}
-
-func (p *OpenAIProvider) TranscriptionModels() []string {
-	return []string{"whisper-1"}
-}
-
-func (p *OpenAIProvider) LLMModels() []string {
-	return []string{"gpt-4o-mini", "gpt-4o", "gpt-4-turbo", "gpt-3.5-turbo"}
+func (p *OpenAIProvider) DefaultModel(t ModelType) string {
+	switch t {
+	case Transcription:
+		return "whisper-1"
+	case LLM:
+		return "gpt-4o-mini"
+	}
+	return ""
 }