Address PR review feedback for DISCORD_WEBHOOK_URL env var

- Add DISCORD_WEBHOOK_URL to docker-compose.yml api service environment block
- Add empty placeholder entry in .env for discoverability
- Move DISCORD_WEBHOOK_URL constant to the env-var constants section at top of dependencies.py

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

.env

@@ -6,6 +6,9 @@ SBA_DB_USER_PASSWORD=your_production_password
 # SBa API
 API_TOKEN=Tp3aO3jhYve5NJF1IqOmJTmk
 
+# Integrations
+DISCORD_WEBHOOK_URL=
+
 # Universal
 TZ=America/Chicago
 LOG_LEVEL=INFO

app/dependencies.py

@@ -22,6 +22,9 @@ logger = logging.getLogger("discord_app")
 #     level=log_level
 # )
 
+# Discord integration
+DISCORD_WEBHOOK_URL = os.environ.get("DISCORD_WEBHOOK_URL")
+
 # Redis configuration
 REDIS_HOST = os.environ.get("REDIS_HOST", "localhost")
 REDIS_PORT = int(os.environ.get("REDIS_PORT", "6379"))
@@ -503,9 +506,6 @@ def update_season_pitching_stats(player_ids, season, db_connection):
         raise
 
 
-DISCORD_WEBHOOK_URL = os.environ.get("DISCORD_WEBHOOK_URL")
-
-
 def send_webhook_message(message: str) -> bool:
     """
     Send a message to Discord via webhook.

docker-compose.yml

@@ -34,6 +34,7 @@ services:
       - REDIS_HOST=sba_redis
       - REDIS_PORT=6379
       - REDIS_DB=0
+      - DISCORD_WEBHOOK_URL=${DISCORD_WEBHOOK_URL}
     depends_on:
       - postgres
       - redis