952e0a2192
Adds com.google.mlkit:genai-image-description as the primary alt-text source — Gemini Nano via AICore produces full descriptive sentences on supported devices. When checkFeatureStatus reports anything other than AVAILABLE (or AICore is missing), the service falls back to the legacy play-services-mlkit-image-labeling keyword join. Both paths sit behind the same MLKitImageLabelService.suggestAltText API; the F-Droid stub is unchanged.