Add local spoken passages with Google retrieval and isolated runtime setup

tools/speech-runtime/windows-model-path.patch

@@ -0,0 +1,42 @@
+--- a/src/whisper.cpp
++++ b/src/whisper.cpp
+@@ -30,6 +30,7 @@
+ #include <cstdio>
+ #include <cstring>
+ #include <fstream>
++#include <filesystem>
+ #include <functional>
+ #include <map>
+ #include <random>
+@@ -3730,13 +3731,7 @@
+ struct whisper_context * whisper_init_from_file_with_params_no_state(const char * path_model, struct whisper_context_params params) {
+     WHISPER_LOG_INFO("%s: loading model from '%s'\n", __func__, path_model);
+-#ifdef _MSC_VER
+-    // Convert UTF-8 path to wide string (UTF-16) for Windows, resolving character encoding issues.
+-    std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
+-    std::wstring path_model_wide = converter.from_bytes(path_model);
+-    auto fin = std::ifstream(path_model_wide, std::ios::binary);
+-#else
+-    auto fin = std::ifstream(path_model, std::ios::binary);
+-#endif
++    // C++17 u8path preserves supplementary Unicode on Windows and UTF-8 elsewhere.
++    auto fin = std::ifstream(std::filesystem::u8path(path_model), std::ios::binary);
+     if (!fin) {
+         WHISPER_LOG_ERROR("%s: failed to open '%s'\n", __func__, path_model);
+         return nullptr;
+@@ -4877,13 +4871,8 @@
+         const char * path_model,
+         struct whisper_vad_context_params params) {
+     WHISPER_LOG_INFO("%s: loading VAD model from '%s'\n", __func__, path_model);
+-#ifdef _MSC_VER
+-    std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
+-    std::wstring path_model_wide = converter.from_bytes(path_model);
+-    auto fin = std::ifstream(path_model_wide, std::ios::binary);
+-#else
+-    auto fin = std::ifstream(path_model, std::ios::binary);
+-#endif
++    // Same strict UTF-8 path contract as the base recognizer.
++    auto fin = std::ifstream(std::filesystem::u8path(path_model), std::ios::binary);
+     if (!fin) {
+         WHISPER_LOG_ERROR("%s: failed to open VAD model '%s'\n", __func__, path_model);
+         return nullptr;