Unify startup: initializer starts every non-test process, Puma and Resque
stop before fork and start again in the child. Only the contender thread
releases the lock. Drop Puma::CLI / single_puma_process? special cases.
Co-authored-by: Thomas Klemm <github@tklemm.eu>
Disable wal_autocheckpoint and run PASSIVE checkpoints from one elected
writer process. Contenders start in console/rake (initializer), Puma
workers (including WEB_CONCURRENCY=auto), and Resque children, with
failover, capped error backoff, and tests for lock takeover.
Co-authored-by: Thomas Klemm <github@tklemm.eu>