Merge branch 'pratik/otel-phase9-metric-gap-fill' into pratik/otel-phase10-workload-validation

# Conflicts:
#	docker/telemetry/grafana/dashboards/fee-market.json
#	docker/telemetry/grafana/dashboards/transaction-overview.json
#	src/xrpld/telemetry/MetricsRegistry.h

src/xrpld/telemetry/MetricsRegistry.cpp

@@ -254,8 +254,30 @@ MetricsRegistry::initSyncInstruments()
         "validations_checked_total", "Total network validations received and checked");
     stateChangesCounter_ =
         meter_->CreateUInt64Counter("state_changes_total", "Total operating mode changes");
-    jqTransOverflowCounter_ = meter_->CreateUInt64Counter(
+    // jq_trans_overflow_total is observed from Overlay's existing cumulative
+    // atomic (Overlay::getJqTransOverflow()) rather than pushed. The overlay
+    // owns the only increment site (PeerImp), so an ObservableCounter reads the
+    // live total each collection cycle without threading a push path through
+    // develop-owned overlay code.
+    jqTransOverflowObservable_ = meter_->CreateInt64ObservableCounter(
         "jq_trans_overflow_total", "Total job queue transaction overflows");
+    jqTransOverflowObservable_->AddCallback(
+        [](opentelemetry::metrics::ObserverResult result, void* state) {
+            auto* self = static_cast<MetricsRegistry*>(state);
+            if (self->callbacksDetached_.load(std::memory_order_acquire))
+                return;
+            try
+            {
+                opentelemetry::nostd::get<opentelemetry::nostd::shared_ptr<
+                    opentelemetry::metrics::ObserverResultT<int64_t>>>(result)
+                    ->Observe(static_cast<int64_t>(self->app_.getOverlay().getJqTransOverflow()));
+            }
+            catch (...)  // NOLINT(bugprone-empty-catch)
+            {
+                // Silently skip on error.
+            }
+        },
+        this);
     ledgerHistoryMismatchCounter_ = meter_->CreateUInt64Counter(
         "ledger_history_mismatch_total", "Total built-vs-validated ledger mismatches by reason");
     txqExpiredCounter_ = meter_->CreateUInt64Counter(
@@ -1458,15 +1480,6 @@ MetricsRegistry::incrementStateChanges()
 #endif
 }
 
-void
-MetricsRegistry::incrementJqTransOverflow()
-{
-#ifdef XRPL_ENABLE_TELEMETRY
-    if (enabled_ && jqTransOverflowCounter_)
-        jqTransOverflowCounter_->Add(1);
-#endif
-}
-
 void
 MetricsRegistry::incrementLedgerHistoryMismatch(std::string_view reason)
 {

src/xrpld/telemetry/MetricsRegistry.h

@@ -36,7 +36,6 @@
                     |       +-- validations_sent_total
                     |       +-- validations_checked_total
                     |       +-- state_changes_total
-                    |       +-- jq_trans_overflow_total
                     |       +-- ledger_history_mismatch_total{reason}
                     |       +-- txq_expired_total
                     |       +-- txq_dropped_total{reason}
@@ -61,6 +60,7 @@
                             +-- State tracking (mode value, time in state)
                             +-- Storage detail (NuDB sizes)
                             +-- Validation agreement (1h/24h pct, counts)
+                            +-- jq_trans_overflow_total (observed from Overlay)
 
     Control-flow for async gauges:
 
@@ -347,13 +347,6 @@ public:
     void
     incrementStateChanges();
 
-    /** Increment the jq_trans_overflow_total counter.
-        Called when the job queue transaction limit overflows (mirrors
-        Overlay::incJqTransOverflow()).
-    */
-    void
-    incrementJqTransOverflow();
-
     /** Increment the ledger_history_mismatch_total counter for a reason.
         Called from LedgerHistory::handleMismatch() once the mismatch has
         been classified. The reason label turns fork diagnosis from a
@@ -517,9 +510,10 @@ private:
     /// Counter: state_changes_total — incremented on operating mode transitions.
     opentelemetry::nostd::unique_ptr<opentelemetry::metrics::Counter<uint64_t>>
         stateChangesCounter_;
-    /// Counter: jq_trans_overflow_total — incremented on job queue transaction overflows.
-    opentelemetry::nostd::unique_ptr<opentelemetry::metrics::Counter<uint64_t>>
-        jqTransOverflowCounter_;
+    /// ObservableCounter: jq_trans_overflow_total — observed from
+    /// Overlay::getJqTransOverflow() (cumulative overflow tally owned by the overlay).
+    opentelemetry::nostd::shared_ptr<opentelemetry::metrics::ObservableInstrument>
+        jqTransOverflowObservable_;
     /// Counter: ledger_history_mismatch_total{reason} — incremented per classified
     /// built-vs-validated ledger mismatch.
     opentelemetry::nostd::unique_ptr<opentelemetry::metrics::Counter<uint64_t>>