mtmd: support Qwen3-TTS (note: breaking change to llama-tts binary) (#26254)

* convert text model

* main model load ok

* convert encoder ok

* speaker encoder loading ok

* speaker enc graph

* adapt vocab for backbone (with some tricks)

* add suppress_tokens

* poc new mtmd gen api

* convert code_predictor to gguf

* load gen_code model ok

* add clip_encode

* wire up

* code gen cgraph init version

Co-authored-by: Pascal <admin@serveurperso.com>

* code2wav convert to gguf

* code2wav graph ok

* wire up in/out

* (wip) subgraph

* wire up

* wip, correct code2wav

* demo (to be removed)

* code2wav preserve kv between calls

* demo voice clone

* llama: add llama_model_get_tok_embd

* mtmd_helper_gen_audio API

* fix clamp cold prefix

Co-authored-by: Pascal <admin@serveurperso.com>

* fuse snake op

Co-authored-by: Pascal <admin@serveurperso.com>

* demo: use proper sampling

* update dev docs

* polymorphism helper

* revamp llama-tts binary

* update docs

* fix compile

* fix lint

* nits

* add guide + docs

* more timings info

* clean up code comments

* security fixes

* update docs

* use ggml_build_forward_select, clean up comments

* fix ci

* use ISO 639-1 language code

* rename CODE2WAV --> GEN_WAV, update docs

* clean up

* clean up tts.cpp

* add seq_id

* add step_prompt()

* mtmd_helper_model_can_chat

* clean up comments

---------

Co-authored-by: Pascal <admin@serveurperso.com>

tools/mtmd/mtmd-cli.cpp

@@ -116,6 +116,14 @@ struct mtmd_cli_context {
             exit(1);
         }
 
+        init_vision_context(params);
+
+        if (!mtmd_helper_model_can_chat(lctx, ctx_vision.get())) {
+            LOG_ERR("Model does not support chat mode\n");
+            LOG_ERR("Hint: for TTS models, please use llama-tts\n");
+            exit(1);
+        }
+
         if (!llama_model_chat_template(model, nullptr) && params.chat_template.empty()) {
             LOG_ERR("Model does not have chat template.\n");
             LOG_ERR("  For old llava models, you may need to use '--chat-template vicuna'\n");
@@ -129,8 +137,6 @@ struct mtmd_cli_context {
         chat_history.clear();
         LOG_INF("%s: chat template example:\n%s\n", __func__, common_chat_format_example(tmpls.get(), params.use_jinja, params.default_template_kwargs).c_str());
 
-        init_vision_context(params);
-
         // load antiprompt tokens for legacy templates
         if (params.chat_template == "vicuna") {
             antiprompt_tokens = common_tokenize(lctx, "ASSISTANT:", false, true);