fix(aggregate): release lock on failure

[XOlegator]

What changed

• replaced stale lock-file TTL handling with file locking via flock in aggregate
• guaranteed lock release in finally so failed aggregate runs no longer block later runs
• made register-crontab emit an explicit PHP binary invocation with --no-interaction
• updated the lock notification wording and deployment docs

Why

Aggregate could leave var/aggregate.lock behind after any unhandled failure. That caused later cron runs to report a false concurrent execution state until the TTL expired.

Impact

• aggregate no longer gets stuck behind stale lock files after runtime failures
• cron examples and generated crontab entries now pin the intended PHP binary

Validation

• php -l src/Command/AggregateCommand.php
• php -l src/Command/InitCommand.php
• php bin/console lint:twig templates/lock_notification.html.twig
• php bin/console doctrine:migrations:migrate --no-interaction
• php bin/console aggregate --no-interaction