mtmd, common: various fixes (#27071)

* apply fixes

* cont

* revert gguf fix

src/models/dflash.cpp

@@ -43,6 +43,8 @@ void llama_model_dflash::load_arch_hparams(llama_model_loader & ml) {
         ml.get_key(LLM_KV_HYPER_CONNECTION_EPSILON,             hparams.dsv4_hc_eps);
         ml.get_arr(LLM_KV_ATTENTION_COMPRESS_RATIOS,            hparams.dsv4_compress_ratios, false);
 
+        GGML_ASSERT(hparams.dsv4_o_group_count > 0); // avoid div by zero
+
         if (hparams.expert_gating_func != LLAMA_EXPERT_GATING_FUNC_TYPE_SQRT_SOFTPLUS) {
             throw std::runtime_error("DSpark DSV4 draft expects sqrtsoftplus MoE scoring");
         }

src/models/minimax-m3.cpp

@@ -25,6 +25,8 @@ void llama_model_minimax_m3::load_arch_hparams(llama_model_loader & ml) {
     ml.get_key(LLM_KV_ATTENTION_INDEXER_LOCAL_BLOCKS,  hparams.indexer_local_blocks);
     msa_p = { (int) hparams.indexer_block_size, (int) hparams.indexer_top_k, (int) hparams.indexer_local_blocks };
 
+    GGML_ASSERT(hparams.indexer_block_size > 0); // avoid div by zero
+
     switch (hparams.n_layer()) {
         case 60: type = LLM_TYPE_428B_A23B; break;
         default: type = LLM_TYPE_UNKNOWN;