feat: wire MTP draft-mtp speculative decoding + restore mtp.test.js.

Signed-off-by: Marcus Edel <marcus.edel@collabora.com>

Author: zoq

packages/llm-llamacpp/addon/src/model-interface/LlamaModel.cpp

@@ -19,6 +19,7 @@
 #include <common/chat.h>
 #include <common/common.h>
 #include <common/log.h>
+#include <common/speculative.h>
 #include <inference-addon-cpp/Errors.hpp>
 #include <llama.h>
 #ifdef __APPLE__
@@ -1008,6 +1009,8 @@ LlamaModel::singleRuntimeStatsLocked() const {
       {"contextSlides",
        static_cast<int64_t>(state_->llmContext_->getNSlides())},
       {"avgConcurrentSeq", 1.0},
+      {"draftAccepted", state_->llmContext_->getDraftAccepted()},
+      {"draftTotal", state_->llmContext_->getDraftTotal()},
       {"backendDevice", runtimeBackendDevice_}};
 }
 
@@ -1308,15 +1311,11 @@ void LlamaModel::commonParamsParse(
 
   for (const std::string& key : {"spec-type", "spec_type"}) {
     if (auto iter = configFilemap.find(key); iter != configFilemap.end()) {
-      const auto requested = split(iter->second, ',');
-      if (std::find(requested.begin(), requested.end(), "draft-mtp") !=
-          requested.end()) {
-        throw qvac_errors::StatusError(
-            ADDON_ID,
-            qvac_errors::general_error::toString(
-                qvac_errors::general_error::InvalidArgument),
-            "spec-type=draft-mtp is not supported");
-      }
+      auto types =
+          common_speculative_types_from_names(split(iter->second, ','));
+      params.speculative.types.insert(
+          params.speculative.types.end(), types.begin(), types.end());
+      configFilemap.erase(iter);
     }
   }
 

packages/llm-llamacpp/addon/src/model-interface/LlmContext.hpp

@@ -281,6 +281,14 @@ class LlmContext { // NOLINT(cppcoreguidelines-special-member-functions)
    */
   virtual void resetNSlides() = 0;
 
+  /**
+   * Speculative-decoding counters for the most recent generation. Default 0
+   * for contexts without speculative decoding; the single-prompt MTP path
+   * overrides these to surface draft acceptance via RuntimeStats.
+   */
+  [[nodiscard]] virtual int64_t getDraftAccepted() const { return 0; }
+  [[nodiscard]] virtual int64_t getDraftTotal() const { return 0; }
+
   /**
    * The load media method. It loads the media from memory buffer.
    * Default implementation does nothing (for text-only contexts).