Add Discord sharding support and related configurations

Enhance the bot's architecture by introducing sharding capabilities, allowing for better scalability and performance. Update environment files to include sharding options, and modify the bot's core logic to handle shard connections and latencies. Implement shard-specific logging and API synchronization, ensuring that only the primary shard performs certain tasks. Update API schemas and routes to reflect shard information, improving the overall status reporting and monitoring of the bot's performance across multiple shards.

.env.docker.example

@@ -7,6 +7,12 @@ brand_name=Axiom
 OWNER_IDS=YOUR_DISCORD_USER_ID_HERE
 DASHBOARD_ADMIN_IDS=YOUR_DISCORD_USER_ID_HERE
 
+# Sharding — leave unset for auto (recommended). Multi-process: same TOKEN, shared bot-db volume.
+# SHARD_COUNT=
+# SHARD_IDS=0,1
+# SHARD_PRIMARY=
+# Enable API only on the primary shard process.
+
 # Shared secret — must match between bot API and dashboard
 DASHBOARD_API_KEY=generate_a_long_random_secret_here