Add Redix connection resilience options to Exq config

Configures Redix (Exq's Redis client) with better connection handling:
- sync_connect: true - fail fast if Redis unavailable at startup
- exit_on_disconnection: false - don't crash process on disconnect
- backoff_initial: 500ms, backoff_max: 30s - retry with exponential backoff

This helps Exq survive temporary Redis disconnections without crashing,
reducing the frequency of Protocol.UndefinedError crashes in Exq.Node.Server.

lib/towerops/exq_supervisor.ex

@@ -72,12 +72,27 @@ defmodule Towerops.ExqSupervisor do
       namespace: "exq",
       concurrency: 10,
       queues: ["default", "discovery", "polling", "monitoring", "maintenance"],
-      # Increase max retries and backoff for better Redis connection recovery
+      # Poll settings - how long to wait for Redis responses
+      poll_timeout: 50,
+      scheduler_poll_timeout: 200,
+      scheduler_enable: true,
+      # Job retry settings
       max_retries: 50,
-      # Exponential backoff starting at 500ms
-      backoff: 500,
-      # Add shutdown timeout to allow jobs to complete
-      shutdown_timeout: 25_000
+      # Exponential backoff starting at 500ms, up to 60s
+      mode: :default,
+      shutdown_timeout: 30_000,
+      # Redix connection options for better resilience
+      redis_options: [
+        # Synchronous connect to fail fast if Redis unavailable
+        sync_connect: true,
+        # Don't exit process on disconnection - let Exq handle it
+        exit_on_disconnection: false,
+        # Connection timeout
+        timeout: 5_000,
+        # Backoff for reconnection attempts
+        backoff_initial: 500,
+        backoff_max: 30_000
+      ]
     ]
   end
 end