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-context.cpp

@@ -5660,7 +5660,7 @@ void server_routes::init_routes() {
                 scores.push_back(result->scores);
                 n_tokens += result->n_tokens;
             }
-            answers[question.id] = decision.format_answer(question, scores);
+            answers[question.id] = decision.format_answer(question, scores, !files.empty());
         }
 
         res->ok(json{