[wieslawgolec]

Summary

Hardened filesystem queue transport for Mautic 7 (v1.1.0) with a Mautic-4-style retry state machine, middleware-owned temporary retries, recovery, backoff, keepalive, updated docs, and a full PHPUnit + concurrent race-condition test suite (CI on PHP 8.2 / 8.5 / 8.6).

Root cause fixed

Commit d057a771 introduced listMessageIdsGenerator() which yielded basenames only. Downstream code treated those values as full paths → messages were not created/read under the correct var/queue/… location.

This PR replaces that design with an ID-centric claim path: ready IDs are listed, full paths are always built via helpers, and claim is a single atomic rename().

State machine

Stage	Filename	Actor
First enqueue	{id}.message	send()
Claim	{id}.processing	tryClaim()
Temporary fail	rename → {id}.message.retry.N	Middleware + requeueWithRetry() → Worker ack()
Claim after retry	{id}.processing.retry.N	tryClaim()
Final fail	file deleted	Worker reject() → failed transport
Stuck recovery	.processing* → ready (same attempt)	recoverStuckProcessingFiles()

Guarantees:

• A message is never in both the active queue and the failed queue at the same time
• Temporary failures do not create a second copy (same file is renamed back to ready)
• Concurrent workers cannot double-claim the same message (atomic rename(); loser gets null)

Main changes

New

• Messenger/Stamp/AttemptStamp.php
• Messenger/Middleware/FilesystemRetryMiddleware.php
• PHPUnit suite (tests/Unit/…, tests/Concurrency/…)
• GitHub Actions workflow (.github/workflows/tests.yml)
• phpunit.xml.dist, tests/bootstrap.php, standalone CoreParametersHelper stub for CI

Updated

• Messenger/Transport/FileSystemTransport.php — hardened rewrite
• Messenger/Transport/FileSystemTransportFactory.php — cleaned (no unused PathsHelper)
• Config/services.php — registers middleware + transport factory
• Config/config.php — version 1.1.0 + retry/recovery parameters
• composer.json — require-dev + autoload-dev
• README.md — state machine, settings tables, testing, architecture

New config parameters

'filesystem_queue_max_attempts'        => 5,
'filesystem_queue_recovery_timeout'    => 300,  // seconds
'filesystem_queue_recovery_interval'   => 30,
'filesystem_queue_recovery_stuck'      => true,
'filesystem_queue_retry_backoff_base'  => 30,   // exponential seconds
'filesystem_queue_send_max_retries'    => 15,