monitoring: mirror fc-signage-marquee alert group into noc-monitoring K8s target

Mirror of FlowerCore.Notes/scripts/monitoring/alerts.yml fc-signage-marquee
group into the K8s migration target apps/monitoring/noc-monitoring.yaml so
that future migration of the noc1 Podman monitoring stack into RKE2
inherits the marquee alert ruleset automatically.

Three rules added:
  - MarqueeDroppedFramesHigh        (5% / 5min / warning)
  - MarqueeRenderLatencyP99High     (16ms / 10min / warning)
  - MarqueeAnimationDurationDrift   (10% / 15min / info)

All three gated with `unless on() absent_over_time(metric[7d])` so they
don't fire during the metric-not-yet-published window before Track 3
IR-21 source IMPL ships the MarqueeMeter into Common + Web + WPF.

Live source-of-truth (the noc1 Podman Prometheus reads from
/opt/monitoring/prometheus/alerts.yml) was updated and reloaded
in the same session — Notes commit 300daa0 carries the matching
alerts.yml + Grafana fc-signage-dashboard.json change.

Per feedback_monitoring_k8s_target_vs_live_podman: this file is the
forward-looking K8s migration target, NOT what the live Podman
Prometheus reads. ArgoCD-syncing this file does NOT push alerts to
the live monitoring stack.

Companion to:
- FlowerCore.Notes 300daa0 (live alerts.yml + Grafana panels deployed)
- docs/signage/marquee-performance-telemetry-design.md (Track 3 IR-21 spec)
- docs/signage/marquee-animation-phases.md (Track 6 13-phase coverage matrix)

Memory: project_marquee_vr_promotion_landed_2026_05_06

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/monitoring/noc-monitoring.yaml

@@ -1024,6 +1024,72 @@ data:
               summary: "Longhorn node {{ $labels.node }} not Ready"
               description: "Node {{ $labels.node }} reports ready=false (reason: {{ $labels.condition_reason }}). Volumes scheduled to this node will be unavailable until it recovers."
 
+      # ============================================================
+      # FC Signage Marquee Performance — Track 3 + 8 (2026-05-06)
+      # Live-mirrored from FlowerCore.Notes/scripts/monitoring/alerts.yml.
+      # Source-of-truth for the live Podman Prometheus on noc1 is the
+      # Notes file; this K8s ConfigMap exists so a future migration to
+      # in-cluster Prometheus inherits the ruleset automatically.
+      # See feedback_monitoring_k8s_target_vs_live_podman.
+      # ============================================================
+      - name: fc-signage-marquee
+        rules:
+          - alert: MarqueeDroppedFramesHigh
+            expr: |
+              (
+                sum by (renderer, phase, node_id) (rate(marquee_dropped_frames_total[5m]))
+                /
+                sum by (renderer, phase, node_id) (rate(marquee_render_latency_ms_count[5m]))
+              ) > 0.05
+              unless on()
+              absent_over_time(marquee_dropped_frames_total[7d])
+            for: 5m
+            labels:
+              severity: warning
+              service: signage
+              alert_channel: irc
+            annotations:
+              summary: "Marquee dropped-frame rate >5% on {{ $labels.renderer }}/{{ $labels.node_id }} ({{ $labels.phase }})"
+              description: "Renderer {{ $labels.renderer }} on {{ $labels.node_id }} drops >5% of frames during {{ $labels.phase }}. Animation visibly stuttery."
+
+          - alert: MarqueeRenderLatencyP99High
+            expr: |
+              histogram_quantile(
+                0.99,
+                sum by (renderer, phase, node_id, le) (rate(marquee_render_latency_ms_bucket[5m]))
+              ) > 16
+              unless on()
+              absent_over_time(marquee_render_latency_ms_bucket[7d])
+            for: 10m
+            labels:
+              severity: warning
+              service: signage
+              alert_channel: irc
+            annotations:
+              summary: "Marquee render latency p99 > 16ms on {{ $labels.renderer }}/{{ $labels.node_id }} ({{ $labels.phase }})"
+              description: "Per-frame render latency p99 has exceeded the Pi-class 16ms budget for 10 minutes."
+
+          - alert: MarqueeAnimationDurationDrift
+            expr: |
+              abs(
+                histogram_quantile(0.5, sum by (renderer, phase, le) (rate(marquee_animation_duration_ms_bucket[15m])))
+                -
+                on (phase) group_left() avg by (phase) (marquee_animation_duration_target_ms)
+              )
+              /
+              on (phase) group_left() avg by (phase) (marquee_animation_duration_target_ms)
+              > 0.10
+              unless on()
+              absent_over_time(marquee_animation_duration_ms_bucket[7d])
+            for: 15m
+            labels:
+              severity: info
+              service: signage
+              alert_channel: irc
+            annotations:
+              summary: "Marquee animation duration drifting > 10% on {{ $labels.renderer }} ({{ $labels.phase }})"
+              description: "Median observed cycle duration deviates from target DurationMs by >10%. Could indicate browser tab throttling, GPU pressure, or phase-advancement bug."
+
 # =============================================================================
 # ConfigMap: Blackbox Exporter Configuration
 # =============================================================================