fix(queue): add Redis database selection support for queue.redis configuration

[Copilot]

Users cannot specify a Redis database number (other than 0) for the queue engine, despite this being supported for the stat engine and by the underlying redisdb-stream library.

Changes

• Configuration: Added db field to SectionRedisQueue struct with viper loading support
• Queue initialization: Pass db parameter to redisdb.NewWorker() via WithDB() option
• Tests: Added coverage for config file and environment variable loading

Usage

queue:
  engine: "redis"
  redis:
    addr: 127.0.0.1:6379
    db: 5  # Previously forced to 0

Or via environment variable:

GORUSH_QUEUE_REDIS_DB=5

Both queue and stat engines can now use separate Redis databases, enabling better data isolation.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• redis
  • Triggering command: /tmp/go-build904522946/b257/redis.test -test.testlogfile=/tmp/go-build904522946/b257/testlog.txt -test.paniconexit0 -test.timeout=10m0s -test.v=true (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>can not specify redis db</issue_title>
<issue_description>can not specify redis db which is not 0</issue_description>

Comments on the Issue (you are @copilot in this section)

@appleboy I will take it.

• Fixes can not specify redis db #846

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