diff --git a/VERSION b/VERSION
index fe50cf9..a1c59a3 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.6.3-dev
+0.6.3-speechdiag
diff --git a/boards/m5stack_stopwatch/audio_backend.cpp b/boards/m5stack_stopwatch/audio_backend.cpp
index 6240f0d..7c96e85 100644
--- a/boards/m5stack_stopwatch/audio_backend.cpp
+++ b/boards/m5stack_stopwatch/audio_backend.cpp
@@ -12,6 +12,7 @@
 #include "esp_log.h"
 #include "esp_timer.h"
 #include "esp_heap_caps.h"
+#include "mbedtls/sha256.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/queue.h"
 #include "freertos/idf_additions.h"
@@ -53,6 +54,13 @@ std::atomic<uint32_t> s_speech_id{0};
 std::atomic<bool> s_approval_tone{false};
 std::mutex s_speech_lock;
 TickType_t s_speech_progress_at;
+mbedtls_sha256_context s_diag_accepted;
+size_t s_diag_accepted_bytes=0;unsigned s_diag_frames=0;
+void diag_digest(mbedtls_sha256_context *ctx, char *hex) {
+    unsigned char digest[32];mbedtls_sha256_finish(ctx,digest);
+    static const char digits[]="0123456789abcdef";
+    for(unsigned i=0;i<32;++i){hex[2*i]=digits[digest[i]>>4];hex[2*i+1]=digits[digest[i]&15];}hex[64]=0;
+}
 
 
 
@@ -196,6 +204,8 @@ void audio_task(void *)
 void speech_task(void *)
 {
     auto *frame = new SpeechFrame{};
+    mbedtls_sha256_context written_ctx;mbedtls_sha256_init(&written_ctx);
+    uint32_t written_id=0;size_t written_bytes=0;unsigned written_frames=0;int64_t first_us=0;
     const TickType_t idle_timeout = pdMS_TO_TICKS(3000);
     while (true) {
         TickType_t wait = idle_timeout;
@@ -220,12 +230,22 @@ void speech_task(void *)
             continue;
         }
         std::lock_guard<std::mutex> lock(s_audio_mode_lock);
-        if (s_speech_id != frame->id || s_recording || s_approval_tone) continue;
+        if (s_speech_id != frame->id || s_recording || s_approval_tone) {
+            ESP_LOGW(TAG,"[DIAG_SPEECH] drop generation=%u active=%u recording=%d approval=%d bytes=%u",frame->id,s_speech_id.load(),s_recording.load(),s_approval_tone.load(),unsigned(frame->size));continue;
+        }
+        if(written_id!=frame->id){written_id=frame->id;written_bytes=0;written_frames=0;first_us=esp_timer_get_time();mbedtls_sha256_starts(&written_ctx,0);ESP_LOGI(TAG,"[DIAG_SPEECH] first_write generation=%u device_us=%lld",written_id,(long long)first_us);}
         bool ok = true;
         for (size_t offset=0; offset<frame->size && s_speech_id==frame->id && !s_recording && !s_approval_tone; offset+=512) {
-            if (esp_codec_dev_write(s_codec_dev, frame->pcm+offset, std::min<size_t>(512,frame->size-offset))!=ESP_OK) { ok=false; break; }
+            const size_t bytes=std::min<size_t>(512,frame->size-offset);
+            const int rc=esp_codec_dev_write(s_codec_dev,frame->pcm+offset,bytes);
+            if(rc!=ESP_OK){ESP_LOGW(TAG,"[DIAG_SPEECH] codec_write_fail rc=%d total=%u",rc,unsigned(written_bytes));ok=false;break;}
+            mbedtls_sha256_update(&written_ctx,frame->pcm+offset,bytes);written_bytes+=bytes;
         }
+        if(frame->size)++written_frames;
+        if(written_frames==1 || written_frames%10==0 || frame->end)ESP_LOGI(TAG,"[DIAG_SPEECH] written generation=%u frames=%u bytes=%u queue=%u",written_id,written_frames,unsigned(written_bytes),unsigned(uxQueueMessagesWaiting(s_speech_queue)));
         if (!ok || frame->end) {
+            char hex[65];diag_digest(&written_ctx,hex);
+            ESP_LOGI(TAG,"[DIAG_SPEECH] playback_end generation=%u reason=%s written_bytes=%u elapsed_ms=%lld sha256=%s",written_id,ok?"end":"codec-error",unsigned(written_bytes),(long long)((esp_timer_get_time()-first_us)/1000),hex);
             uint32_t expected=frame->id;
             s_speech_id.compare_exchange_strong(expected,0);
         }
@@ -420,7 +440,9 @@ bool audio_backend_take_capture(AudioCaptureFrame *frame)
 
 bool audio_backend_speech_start(uint32_t id) {
     std::lock_guard<std::mutex> guard(s_speech_lock);
-    if (!s_ready || !id || s_recording || s_approval_tone) return false;
+    if (!s_ready || !id || s_recording || s_approval_tone) {ESP_LOGW(TAG,"[DIAG_SPEECH] start_reject ready=%d recording=%d approval=%d",s_ready,s_recording.load(),s_approval_tone.load());return false;}
+    mbedtls_sha256_init(&s_diag_accepted);mbedtls_sha256_starts(&s_diag_accepted,0);s_diag_accepted_bytes=0;s_diag_frames=0;
+    ESP_LOGI(TAG,"[DIAG_SPEECH] backend_start generation=%u device_us=%lld recording=0 approval=0",id,(long long)esp_timer_get_time());
     s_speech_id=0;
     xQueueReset(s_speech_queue); xQueueReset(s_notification_queue);
     s_speech_progress_at=xTaskGetTickCount();
@@ -437,8 +459,12 @@ bool audio_backend_speech_push(uint32_t id, const uint8_t *pcm, size_t size, boo
     frame.id=id; frame.size=size; frame.end=end;
     if (size) std::copy(pcm,pcm+size,frame.pcm);
     if (xQueueSend(s_speech_queue,&frame,0)!=pdTRUE) {
+        ESP_LOGW(TAG,"[DIAG_SPEECH] queue_full generation=%u accepted=%u queue=%u",id,unsigned(s_diag_accepted_bytes),unsigned(uxQueueMessagesWaiting(s_speech_queue)));
         s_speech_id=0; xQueueReset(s_speech_queue); return false;
     }
+    if(size){mbedtls_sha256_update(&s_diag_accepted,pcm,size);s_diag_accepted_bytes+=size;++s_diag_frames;}
+    if(s_diag_frames==1 || s_diag_frames%10==0 || end)ESP_LOGI(TAG,"[DIAG_SPEECH] accepted generation=%u frames=%u bytes=%u queue=%u",id,s_diag_frames,unsigned(s_diag_accepted_bytes),unsigned(uxQueueMessagesWaiting(s_speech_queue)));
+    if(end){char hex[65];diag_digest(&s_diag_accepted,hex);ESP_LOGI(TAG,"[DIAG_SPEECH] accepted_end generation=%u bytes=%u sha256=%s",id,unsigned(s_diag_accepted_bytes),hex);}
     s_speech_progress_at=xTaskGetTickCount();
     return true;
 }
diff --git a/boards/m5stack_stopwatch/board.cpp b/boards/m5stack_stopwatch/board.cpp
index 24cebbe..c443f2e 100644
--- a/boards/m5stack_stopwatch/board.cpp
+++ b/boards/m5stack_stopwatch/board.cpp
@@ -2898,7 +2898,7 @@ bool speech_settings_message(cJSON *root, const std::string &type) {
     const auto id=js(root,"speech_id");
     auto number=[&](const char *key) {const auto *v=cJSON_GetObjectItemCaseSensitive(root,key);return cJSON_IsNumber(v)?v->valuedouble:-1;};
     if (type=="speech_start") {
-        if (s_approval.modal() || (s_input_modal!=InputModal::NONE && !(s_input_modal==InputModal::VOICE && s_voice_phase=="SENT")) || js(root,"target")!=selected_target()) {stop_speech();return true;}
+        if (s_approval.modal() || (s_input_modal!=InputModal::NONE && !(s_input_modal==InputModal::VOICE && s_voice_phase=="SENT")) || js(root,"target")!=selected_target()) {ESP_LOGW(TAG,"[DIAG_SPEECH] rejected_start approval=%d modal=%s target_match=%d",s_approval.modal(),modal_name(s_input_modal),js(root,"target")==selected_target());stop_speech();return true;}
         if (s_input_modal==InputModal::VOICE) cancel_input(false,"speech-preemption");
         if (s_speech.start(id,number("sample_rate"),number("bits"),number("channels"))) {
             if (++s_speech_generation==0) ++s_speech_generation;
@@ -2951,7 +2951,8 @@ void board_control_message(const char *json) {
     if(history_message(root,type)) {cJSON_Delete(root);draw_status();return;}
     if (speech_settings_message(root,type)) {cJSON_Delete(root);draw_status();return;}
     if (type.rfind("speech_",0)==0) {
-        cJSON_Delete(root);return;
+        const bool redraw=speech_message(root,type);
+        cJSON_Delete(root);if(redraw) draw_status();return;
     }
     if (type.rfind("voice_",0)==0 && s_input_modal==InputModal::VOICE && js(root,"voice_id")==s_voice_id) {
         if (type=="voice_error") {audio_backend_record_stop(true);s_voice_phase="VOICE ERROR\n"+js(root,"message");s_transcript.clear();}
diff --git a/firmware/main/cloud_client.cpp b/firmware/main/cloud_client.cpp
index e9cec79..aa75d6e 100644
--- a/firmware/main/cloud_client.cpp
+++ b/firmware/main/cloud_client.cpp
@@ -24,6 +24,7 @@
 #include "freertos/event_groups.h"
 #include "freertos/task.h"
 #include "wifi_manager.h"
+#include "../../.cache/lan_config.h" // Isolated diagnostic LAN configuration.
 
 static const char *TAG = "CLOUD";
 static constexpr int CLOUD_RECONNECT_TIMEOUT_MS = 1500;
@@ -141,8 +142,8 @@ static void send_hello(void)
     // playback. Playback stays FROZEN: no speech_playback capability is
     // advertised, so the Gateway never sends speech_start/chunk/end to this
     // firmware and a saved mode cannot re-enable playback.
-    const char *capabilities[]={"agent_target","approval","voice_input","settings","catalog","target-select","permissions","native-interaction","session-create","speech-settings"};
-    cJSON_AddItemToObject(root,"capabilities",cJSON_CreateStringArray(capabilities,10));
+    const char *capabilities[]={"agent_target","approval","voice_input","settings","catalog","target-select","permissions","native-interaction","session-create","speech-settings","speech_playback"};
+    cJSON_AddItemToObject(root,"capabilities",cJSON_CreateStringArray(capabilities,11));
     if (send_json(root)) {
         ESP_LOGI(TAG, "[CLOUD] sent hello device_id=%s", s_device_id);
     }
diff --git a/firmware/main/wifi_manager.cpp b/firmware/main/wifi_manager.cpp
index adfd398..bc4274d 100644
--- a/firmware/main/wifi_manager.cpp
+++ b/firmware/main/wifi_manager.cpp
@@ -1,4 +1,5 @@
 #include "wifi_manager.h"
+#include "../../.cache/lan_config.h" // Isolated diagnostic LAN configuration.
 
 #include <cstdio>
 #include <cstring>