add deepgram api key env var and config support

internal/config/convert.go

@@ -51,6 +51,9 @@ func (c *Config) resolveAPIKeyForProvider(provider string) string {
 	case "elevenlabs":
 		providerName = "elevenlabs"
 		envVar = "ELEVENLABS_API_KEY"
+	case "deepgram":
+		providerName = "deepgram"
+		envVar = "DEEPGRAM_API_KEY"
 	}
 
 	if c.Providers != nil {

internal/config/save.go

@@ -46,6 +46,8 @@ keywords = []
 #   api_key = ""               # Mistral API key (or set MISTRAL_API_KEY env var)
 # [providers.elevenlabs]
 #   api_key = ""               # ElevenLabs API key (or set ELEVENLABS_API_KEY env var)
+# [providers.deepgram]
+#   api_key = ""               # Deepgram API key (or set DEEPGRAM_API_KEY env var)
 
 # ─────────────────────────────────────────────────────────────────────────────
 # Audio Recording