model : add LiquidAI/d1-omni-600M decision model (#30114)

* model : add LiquidAI/d1-omni-600M decision model

Assisted-by: Claude Opus 5.5

* mtmd : keep conformer GLU sigmoid on CUDA

Assisted-by: Claude Opus 5.5

* server : take d1omni audio through images and input_audio, scope memory-less lfm2 to non-causal

Assisted-by: Claude Opus 5.5

* common : rename decision type d1omni to lfm2-d1-omni, server : make images an alias of files

Assisted-by: Claude Opus 5.5

tools/server/server-common.cpp

@@ -157,6 +157,7 @@ std::vector<std::string> server_model_output_modalities(common_decision_type dec
         case COMMON_DECISION_TYPE_CLEF:
         case COMMON_DECISION_TYPE_PPLX_DECIDER:
         case COMMON_DECISION_TYPE_LFM2_D1:
+        case COMMON_DECISION_TYPE_LFM2_D1_OMNI:
             return {"decisions"};
         default:
             // fallback when there is no decision type or the metadata is bad