chore(dev): add local OpenTelemetry backend configuration

docker/docker-compose.dev.yml

@@ -78,6 +78,15 @@ services:
       timeout: 5s
       retries: 5
 
+  otel-lgtm:
+    image: grafana/otel-lgtm:latest
+    ports:
+      - "${OTEL_GRPC_PORT:-4317}:4317"
+      - "${OTEL_HTTP_PORT:-4318}:4318"
+      - "${OTEL_GRAFANA_PORT:-3001}:3000"
+      - "${OTEL_TEMPO_PORT:-3200}:3200"
+    restart: unless-stopped
+
   searxng:
     image: searxng/searxng:2026.3.13-3c1f68c59
     ports:

surfsense_backend/.env.example

@@ -303,8 +303,17 @@ LANGSMITH_PROJECT=surfsense
 # SURFSENSE_ENABLE_BUSY_MUTEX=false
 # SURFSENSE_ENABLE_LLM_TOOL_SELECTOR=false   # adds a per-turn LLM call
 
-# Observability — OTel (also requires OTEL_EXPORTER_OTLP_ENDPOINT)
+# Observability - OTel
 # SURFSENSE_ENABLE_OTEL=false
+# OpenTelemetry - endpoint enables export; absent = no-op.
+# Production should point at an OTel Collector. For local docker-compose.dev.yml,
+# use http://otel-lgtm:4317 instead.
+# OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-collector:4317
+# OTEL_EXPORTER_OTLP_PROTOCOL=grpc                        # or http/protobuf
+# OTEL_SERVICE_NAME=surfsense-backend
+# OTEL_RESOURCE_ATTRIBUTES=deployment.environment=production
+# OTEL_METRIC_EXPORT_INTERVAL=60000                       # ms
+# OTEL_SDK_DISABLED=false                                 # spec kill-switch
 
 # Skills + subagents
 # SURFSENSE_ENABLE_SKILLS=false