fix(obs): make Postgres host configurable and fix PORT_GRAFANA default

POSTGRES_HOST variable (default: archive-db) lets the observability stack
connect to a different Postgres container — needed when only the staging
stack is running (container name: archiv-staging-db-1).

PORT_GRAFANA default changed from 3001 to 3003 to avoid collision with
the staging frontend which occupies 3001.

Closes #601

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.observability.yml

@@ -142,7 +142,7 @@ services:
     container_name: obs-grafana
     restart: unless-stopped
     ports:
-      - "127.0.0.1:${PORT_GRAFANA:-3001}:3000"
+      - "127.0.0.1:${PORT_GRAFANA:-3003}:3000"
     environment:
       GF_SECURITY_ADMIN_PASSWORD: ${GRAFANA_ADMIN_PASSWORD:-changeme}
       GF_USERS_ALLOW_SIGN_UP: "false"
@@ -193,7 +193,7 @@ services:
       obs-glitchtip-db-init:
         condition: service_completed_successfully
     environment:
-      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@archive-db:5432/glitchtip
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST:-archive-db}:5432/glitchtip
       REDIS_URL: redis://obs-redis:6379/0
       SECRET_KEY: ${GLITCHTIP_SECRET_KEY}
       GLITCHTIP_DOMAIN: ${GLITCHTIP_DOMAIN:-http://localhost:3002}
@@ -215,7 +215,7 @@ services:
       obs-redis:
         condition: service_healthy
     environment:
-      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@archive-db:5432/glitchtip
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST:-archive-db}:5432/glitchtip
       REDIS_URL: redis://obs-redis:6379/0
       SECRET_KEY: ${GLITCHTIP_SECRET_KEY}
     networks:
@@ -229,10 +229,10 @@ services:
     environment:
       PGPASSWORD: ${POSTGRES_PASSWORD}
     command: >
-      sh -c "psql -h archive-db -U ${POSTGRES_USER} -tc
+      sh -c "psql -h ${POSTGRES_HOST:-archive-db} -U ${POSTGRES_USER} -tc
       \"SELECT 1 FROM pg_database WHERE datname = 'glitchtip'\" |
       grep -q 1 ||
-      psql -h archive-db -U ${POSTGRES_USER} -c \"CREATE DATABASE glitchtip;\""
+      psql -h ${POSTGRES_HOST:-archive-db} -U ${POSTGRES_USER} -c \"CREATE DATABASE glitchtip;\""
     networks:
       - archiv-net
 

infra/observability/tempo/tempo.yml

@@ -36,9 +36,6 @@ metrics_generator:
       source: tempo
   storage:
     path: /var/tempo/generator/wal
-  processors:
-    - service-graphs
-    - span-metrics
 
 # Tempo HTTP API (port 3200) is unauthenticated. Access is controlled entirely
 # by network isolation: only Grafana (on obs-net) should reach this port.