feat: make all service ports configurable via env variables

- Add API_PORT, INDEXER_PORT, MEILI_PORT, POSTGRES_PORT env variables
- Update docker-compose.yml to use ${VAR:-default} syntax for all ports
- Document new port variables in .env.example
- Allows users to customize ports to avoid conflicts with other services

infra/docker-compose.yml

@@ -6,7 +6,7 @@ services:
       POSTGRES_USER: stripstream
       POSTGRES_PASSWORD: stripstream
     ports:
-      - "5432:5432"
+      - "${POSTGRES_PORT:-5432}:5432"
     volumes:
       - postgres_data:/var/lib/postgresql/data
     healthcheck:
@@ -20,7 +20,7 @@ services:
     env_file:
       - ../.env
     ports:
-      - "7700:7700"
+      - "${MEILI_PORT:-7700}:7700"
     volumes:
       - meili_data:/meili_data
     healthcheck:
@@ -54,7 +54,7 @@ services:
     env_file:
       - ../.env
     ports:
-      - "8080:8080"
+      - "${API_PORT:-8080}:8080"
     volumes:
       - ${LIBRARIES_HOST_PATH:-../libraries}:/libraries
     depends_on:
@@ -77,7 +77,7 @@ services:
     env_file:
       - ../.env
     ports:
-      - "8081:8081"
+      - "${INDEXER_PORT:-8081}:8081"
     volumes:
       - ${LIBRARIES_HOST_PATH:-../libraries}:/libraries
     depends_on: