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

frigate/genai/plugins/azure-openai.py

@@ -13,6 +13,19 @@ overrides what is genuinely Azure-specific:
 - Context size: Azure does not expose a per-model ``max_model_len`` field
   reliably, so we keep the historical 128K default rather than the
   model-name heuristic used by OpenAI.
+
+Transcription is inherited too: :class:`openai.AzureOpenAI` exposes the same
+``audio.transcriptions.create``. Two Azure-specific caveats apply when using
+the ``transcribe`` role:
+
+- ``model`` must be the Azure *deployment* name, not the underlying model name.
+- The ``api-version`` parsed from ``base_url`` must be 2024-06-01 or later;
+  earlier versions have no transcriptions route and the 404 surfaces only as a
+  generic provider error.
+- Because ``model`` is a deployment name, the inherited check that picks
+  ``languages`` over ``language`` for gpt-transcribe cannot fire unless the
+  deployment happens to be named after the model. Name the deployment
+  ``gpt-transcribe`` to get the right field, or leave the language on ``auto``.
 """
 
 import logging