Support using GenAI for audio transcription (#24396)

* Add support for running transcription with GenAI

* Improve audio joining

* Fix GenAI model capability reporting

* Support language correctly

* Migrate existing users to keep english selected

* Fix models

* Fix tests

* Fix accepted null model

* Handle slwo providers

web/public/locales/en/config/global.json

@@ -348,7 +348,7 @@
     },
     "roles": {
       "label": "Roles",
-      "description": "GenAI roles (chat, descriptions, embeddings); one provider per role."
+      "description": "GenAI roles (chat, descriptions, embeddings, transcribe); one provider per role. Only chat, descriptions, and embeddings are granted by default; transcribe must be listed explicitly."
     },
     "provider_options": {
       "label": "Provider options",
@@ -1131,7 +1131,11 @@
     },
     "language": {
       "label": "Transcription language",
-      "description": "Language code used for transcription/translation (for example 'en' for English). See https://whisper-api.com/docs/languages/ for supported language codes."
+      "description": "Language code used for transcription/translation (for example 'en' for English), or 'auto' to let the model detect it. See https://whisper-api.com/docs/languages/ for supported language codes."
+    },
+    "model": {
+      "label": "Audio transcription model or GenAI provider name",
+      "description": "The transcription backend: 'whisper' for Frigate's built-in local models, or the name of a GenAI provider with the transcribe role."
     },
     "device": {
       "label": "Transcription device",

web/public/locales/en/views/settings.json

@@ -1693,7 +1693,8 @@
       "options": {
         "embeddings": "Embedding",
         "descriptions": "Descriptions",
-        "chat": "Chat"
+        "chat": "Chat",
+        "transcribe": "Transcription"
       }
     },
     "semanticSearchModel": {
@@ -1742,6 +1743,14 @@
       "admin": "Admin",
       "viewer": "Viewer",
       "none": "None (deny access)"
+    },
+    "audioTranscriptionModel": {
+      "placeholder": "Select model…",
+      "builtIn": "Built-in Models",
+      "genaiProviders": "GenAI Providers"
+    },
+    "audioTranscriptionModelSize": {
+      "notApplicable": "Not applicable for GenAI providers"
     }
   },
   "globalConfig": {
@@ -1953,7 +1962,8 @@
       "noAudioRole": "No streams have the audio role defined. You must enable the audio role for audio detection to function."
     },
     "audioTranscription": {
-      "audioDetectionDisabled": "Audio detection is not enabled for this camera. Audio transcription requires audio detection to be active."
+      "audioDetectionDisabled": "Audio detection is not enabled for this camera. Audio transcription requires audio detection to be active.",
+      "genaiProviderSelected": "A GenAI provider is selected, so the device and model size settings are ignored."
     },
     "detect": {
       "fpsGreaterThanFive": "Setting the detect FPS higher than 5 is not recommended. Higher values may cause performance issues and will not provide any benefit.",