feat(observability): add GlitchTip error tracking to observability stack

Adds obs-glitchtip, obs-glitchtip-worker, obs-redis, and obs-glitchtip-db-init
services to docker-compose.observability.yml. The one-shot db-init container
creates the dedicated glitchtip database on the existing archive-db PostgreSQL
instance automatically on first stack start.

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

docker-compose.observability.yml

@@ -166,7 +166,75 @@ services:
       - obs-net
 
   # --- Error Tracking: GlitchTip ---
-  #   glitchtip: (see future issue)
+
+  obs-redis:
+    image: redis:7-alpine
+    container_name: obs-redis
+    restart: unless-stopped
+    volumes:
+      - glitchtip_data:/data
+    expose:
+      - "6379"
+    healthcheck:
+      test: ["CMD", "redis-cli", "ping"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+    networks:
+      - obs-net
+
+  obs-glitchtip:
+    image: glitchtip/glitchtip:v4
+    container_name: obs-glitchtip
+    restart: unless-stopped
+    depends_on:
+      obs-redis:
+        condition: service_healthy
+      obs-glitchtip-db-init:
+        condition: service_completed_successfully
+    environment:
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@archive-db:5432/glitchtip
+      REDIS_URL: redis://obs-redis:6379/0
+      SECRET_KEY: ${GLITCHTIP_SECRET_KEY}
+      GLITCHTIP_DOMAIN: ${GLITCHTIP_DOMAIN:-http://localhost:3002}
+      DEFAULT_FROM_EMAIL: ${APP_MAIL_FROM:-noreply@familienarchiv.local}
+      EMAIL_URL: smtp://mailpit:1025
+      GLITCHTIP_MAX_EVENT_LIFE_DAYS: 90
+    ports:
+      - "127.0.0.1:${PORT_GLITCHTIP:-3002}:8080"
+    networks:
+      - archiv-net
+      - obs-net
+
+  obs-glitchtip-worker:
+    image: glitchtip/glitchtip:v4
+    container_name: obs-glitchtip-worker
+    restart: unless-stopped
+    command: ./bin/run-celery-with-beat.sh
+    depends_on:
+      obs-redis:
+        condition: service_healthy
+    environment:
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@archive-db:5432/glitchtip
+      REDIS_URL: redis://obs-redis:6379/0
+      SECRET_KEY: ${GLITCHTIP_SECRET_KEY}
+    networks:
+      - archiv-net
+      - obs-net
+
+  obs-glitchtip-db-init:
+    image: postgres:16-alpine
+    container_name: obs-glitchtip-db-init
+    restart: "no"
+    environment:
+      PGPASSWORD: ${POSTGRES_PASSWORD}
+    command: >
+      sh -c "psql -h 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;\""
+    networks:
+      - archiv-net
 
 networks:
   # Shared network created by the main docker-compose.yml.