[Feature] Add EmbeddingGemma 2 (sub-1B, multilingual, Apache 2.0) as a Smart Search model

• I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request. The feature Add [google/embeddinggemma-2]( as a selectable Smart Search model in Administration > Settings > Machine Learning > Smart Search. Why this model is a strong fit [Google announced EmbeddingGemma 2]( today. For the part Immich cares about, the text + vision config ({"audio_config": None}) is 440M parameters and maps images and search queries into one shared 768-d space — which is exactly the visual/textual pair split smart_search already assumes. • 100+ languages, and it keeps EmbeddingGemma 1's multilingual text quality while fixing its weak code retrieval (+14% MTEB Code). • Apache 2.0, so converted weights can be hosted under the immich-app HF org. The edge case — this is the part I think matters most Immich's smart search quality today has a cost floor. Looking at the searching.md tables, the multilingu…