rtx-csm: Phase 13.6 — emotion metrics for converse_server

Production observability on the Phase 13.4/13.5 stack. Adds Prometheus
counters to the existing /metrics endpoint:

  rtx_csm_reactive_emotion_calls_total          — detector invocations
  rtx_csm_reactive_emotion_total{label=...}     — 5 buckets (neutral,
                                                  calm, sad, angry,
                                                  excited)
  rtx_csm_emotion_aware_llm_applied_total       — LLM augmentations
                                                  that actually fired

Verified end-to-end on Metal: server with Q8 + LoRA + reactive-emotion
+ emotion-aware-llm, 1 bench turn → /metrics shows
calls=1, calm=1 (all other labels 0), llm_applied=1. Lib suite 110/110.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

crates/models/rtx-csm/examples/converse_server.rs

@@ -389,6 +389,18 @@ struct Metrics {
     /// Total turn wall time: turn start → done event sent.
     total_turn_ms_sum: AtomicU64,
     total_turn_ms_count: AtomicU64,
+    /// Reactive emotion observability (Phase 13.6). Each turn that ran
+    /// the detector increments `_calls_total`; the per-label counters
+    /// add to one of the five labels. `emotion_aware_llm_applied_total`
+    /// counts turns where the LLM-history augmentation actually fired
+    /// (only when the label is non-Neutral AND --emotion-aware-llm is on).
+    reactive_emotion_calls_total: AtomicU64,
+    reactive_emotion_neutral_total: AtomicU64,
+    reactive_emotion_calm_total: AtomicU64,
+    reactive_emotion_sad_total: AtomicU64,
+    reactive_emotion_angry_total: AtomicU64,
+    reactive_emotion_excited_total: AtomicU64,
+    emotion_aware_llm_applied_total: AtomicU64,
 }
 
 /// ASR backend wrapped behind a single Mutex so the receive loop can
@@ -916,7 +928,17 @@ async fn metrics_handler(State(shared): State<Arc<Shared>>) -> impl IntoResponse
          # TYPE rtx_csm_conv_total_ms_avg gauge\n\
          rtx_csm_conv_total_ms_avg {}\n\
          # TYPE rtx_csm_total_turn_ms_avg gauge\n\
-         rtx_csm_total_turn_ms_avg {}\n",
+         rtx_csm_total_turn_ms_avg {}\n\
+         # TYPE rtx_csm_reactive_emotion_calls_total counter\n\
+         rtx_csm_reactive_emotion_calls_total {}\n\
+         # TYPE rtx_csm_reactive_emotion_total counter\n\
+         rtx_csm_reactive_emotion_total{{label=\"neutral\"}} {}\n\
+         rtx_csm_reactive_emotion_total{{label=\"calm\"}} {}\n\
+         rtx_csm_reactive_emotion_total{{label=\"sad\"}} {}\n\
+         rtx_csm_reactive_emotion_total{{label=\"angry\"}} {}\n\
+         rtx_csm_reactive_emotion_total{{label=\"excited\"}} {}\n\
+         # TYPE rtx_csm_emotion_aware_llm_applied_total counter\n\
+         rtx_csm_emotion_aware_llm_applied_total {}\n",
         m.turns_total.load(Ordering::Relaxed),
         m.errors_total.load(Ordering::Relaxed),
         m.connections_total.load(Ordering::Relaxed),
@@ -928,6 +950,13 @@ async fn metrics_handler(State(shared): State<Arc<Shared>>) -> impl IntoResponse
         m.llm_to_first_audio_ms_sum.load(Ordering::Relaxed) / llm_to_audio_count,
         m.conv_total_ms_sum.load(Ordering::Relaxed) / conv_count,
         m.total_turn_ms_sum.load(Ordering::Relaxed) / total_count,
+        m.reactive_emotion_calls_total.load(Ordering::Relaxed),
+        m.reactive_emotion_neutral_total.load(Ordering::Relaxed),
+        m.reactive_emotion_calm_total.load(Ordering::Relaxed),
+        m.reactive_emotion_sad_total.load(Ordering::Relaxed),
+        m.reactive_emotion_angry_total.load(Ordering::Relaxed),
+        m.reactive_emotion_excited_total.load(Ordering::Relaxed),
+        m.emotion_aware_llm_applied_total.load(Ordering::Relaxed),
     );
     (
         StatusCode::OK,
@@ -1293,11 +1322,34 @@ async fn handle_connection(mut socket: WebSocket, shared: Arc<Shared>) {
                 .len()
                 .saturating_sub((PCM_RATE as f32 * 2.0) as usize);
             let speech = &user_audio_24k[..trim_to];
+            shared
+                .metrics
+                .reactive_emotion_calls_total
+                .fetch_add(1, Ordering::Relaxed);
             match rtx_csm::audio_io::resample(speech, PCM_RATE, 16_000) {
                 Ok(speech_16k) => {
                     let det = rtx_csm::ser::ProsodyDetector::default();
                     let label = rtx_csm::ser::EmotionDetector::classify(&det, &speech_16k)
                         .unwrap_or(rtx_csm::ser::EmotionLabel::Neutral);
+                    // Per-label counters.
+                    let bucket = match label {
+                        rtx_csm::ser::EmotionLabel::Neutral => {
+                            &shared.metrics.reactive_emotion_neutral_total
+                        }
+                        rtx_csm::ser::EmotionLabel::Calm => {
+                            &shared.metrics.reactive_emotion_calm_total
+                        }
+                        rtx_csm::ser::EmotionLabel::Sad => {
+                            &shared.metrics.reactive_emotion_sad_total
+                        }
+                        rtx_csm::ser::EmotionLabel::Angry => {
+                            &shared.metrics.reactive_emotion_angry_total
+                        }
+                        rtx_csm::ser::EmotionLabel::Excited => {
+                            &shared.metrics.reactive_emotion_excited_total
+                        }
+                    };
+                    bucket.fetch_add(1, Ordering::Relaxed);
                     if label == rtx_csm::ser::EmotionLabel::Neutral {
                         None // fall back to static --emotion-hint
                     } else {
@@ -1362,6 +1414,10 @@ async fn handle_connection(mut socket: WebSocket, shared: Arc<Shared>) {
                         "{}\n\n[user audio tone: {label} — adjust your response in tone and content to match]",
                         last.content
                     );
+                    shared
+                        .metrics
+                        .emotion_aware_llm_applied_total
+                        .fetch_add(1, Ordering::Relaxed);
                 }
             }
             h