fix: use valid Redis log levels and add log level comments to all containers

Redis only supports debug|verbose|notice|warning -- not info or error.
The command was using ${LOG_LEVEL:-info} which resolved to INFO in
production (from workflow env), causing Redis to crash loop. Hardcode
the correct Redis-native levels (debug for dev, warning for prod) and
add available log level comments above every container's log setting.

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

docker-compose.yml

@@ -11,6 +11,7 @@ services:
     command:
       - --configFile=/etc/traefik/traefik.yml
     environment:
+      # Traefik log levels: TRACE | DEBUG | INFO | WARN | ERROR
       LOG_LEVEL: debug
       CLOUDFLARE_DNS_API_TOKEN_FILE: /run/secrets/cloudflare-dns-token
     ports:
@@ -113,6 +114,7 @@ services:
       NODE_ENV: production
       CONFIG_PATH: /app/config/production.yml
       SECRETS_DIR: /run/secrets
+      # Pino log levels: trace | debug | info | warn | error | fatal
       LOG_LEVEL: debug
       # Service references
       DATABASE_HOST: mvp-postgres
@@ -189,6 +191,7 @@ services:
     container_name: mvp-ocr
     restart: unless-stopped
     environment:
+      # Python log levels: DEBUG | INFO | WARNING | ERROR | CRITICAL
       LOG_LEVEL: debug
       REDIS_HOST: mvp-redis
       REDIS_PORT: 6379
@@ -231,11 +234,13 @@ services:
       POSTGRES_PASSWORD_FILE: /run/secrets/postgres-password
       POSTGRES_INITDB_ARGS: --encoding=UTF8
       LOG_LEVEL: debug
+      # PostgreSQL log statements: none | ddl | mod | all
       POSTGRES_LOG_STATEMENT: all
+      # Minimum query duration to log: -1 (disabled) | 0 (all) | N (ms threshold)
       POSTGRES_LOG_MIN_DURATION_STATEMENT: 0
       PGDATA: /var/lib/postgresql/data/pgdata
     volumes:
-      - mvp_postgres_data:/var/lib/postgresql/data
+      - mvp_postgres_data:/var/lib/postgresql/data/pgdata
       # Secrets (K8s Secrets equivalent)
       - ./secrets/app/postgres-password.txt:/run/secrets/postgres-password:ro
     networks:
@@ -259,9 +264,8 @@ services:
     image: ${REGISTRY_MIRRORS:-git.motovaultpro.com/egullickson/mirrors}/redis:8.4-alpine
     container_name: mvp-redis
     restart: unless-stopped
-    command: redis-server --appendonly yes --loglevel ${LOG_LEVEL:-info}
-    environment:
-      LOG_LEVEL: debug
+    # Redis log levels: debug | verbose | notice | warning
+    command: redis-server --appendonly yes --loglevel debug
     volumes:
       - mvp_redis_data:/data
     networks: