P4DEVOPS-11504: pass redis_reconnect_attempts to API redis connection

[smahima27]

Problem

On startup, vmpooler-dev repeatedly hits Redis::CannotConnectError because the API thread creates its Redis connection without redis_reconnect_attempts:

# Before — uses default reconnect_attempts: 10 (10 immediate retries, no delay)
Vmpooler.new_redis(redis_host, redis_port, redis_password)

The manager thread correctly passed the configured value, which is the exponential-backoff array [0, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512]. The API did not, so its 10 instant retries exhausted before Redis was ready.

This only surfaces in dev because dev Redis has very limited resources (13m CPU / 96Mi memory) and takes longer to start, while prod Redis is already warm on restart.

Fix

Pass redis_reconnect_attempts to Vmpooler.new_redis in the API thread, consistent with the manager.

# After — uses configured exponential backoff
Vmpooler.new_redis(redis_host, redis_port, redis_password, redis_reconnect_attempts)