Fix stale lock issue causing scheduled tasks to stop (#4539)

## Problem
Scheduled tasks, backups, and auto-updates stopped working after 1-2 months
with error: MaxAttemptsExceededException: App\Jobs\ScheduledJobManager has
been attempted too many times.

Root cause: ScheduledJobManager used WithoutOverlapping with only
releaseAfter(60), causing locks without expiration (TTL=-1) that persisted
indefinitely when jobs hung or processes crashed.

## Solution

### Part 1: Prevention (Future Locks)
- Added expireAfter(60) to ScheduledJobManager middleware
- Lock now auto-expires after 60 seconds (matches everyMinute schedule)
- Changed from releaseAfter(60) to expireAfter(60)->dontRelease()
- Follows Laravel best practices and matches other Coolify jobs

### Part 2: Recovery (Existing Locks)
- Enhanced cleanup:redis command with --clear-locks flag
- Scans Redis for stale locks (TTL=-1) and removes them
- Called automatically during app:init on startup/upgrade
- Provides immediate recovery for affected instances

## Changes
- app/Jobs/ScheduledJobManager.php: Added expireAfter(60)->dontRelease()
- app/Console/Commands/CleanupRedis.php: Added cleanupCacheLocks() method
- app/Console/Commands/Init.php: Auto-clear locks on startup
- tests/Unit/ScheduledJobManagerLockTest.php: Test to prevent regression
- STALE_LOCK_FIX.md: Complete documentation

## Testing
- Unit tests pass (2 tests, 8 assertions)
- Code formatted with Pint
- Matches pattern used by CleanupInstanceStuffsJob

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/Jobs/ScheduledJobManager.php

@@ -52,7 +52,8 @@ class ScheduledJobManager implements ShouldQueue
     {
         return [
             (new WithoutOverlapping('scheduled-job-manager'))
-                ->releaseAfter(60), // Release the lock after 60 seconds if job fails
+                ->expireAfter(60)   // Lock expires after 1 minute to prevent stale locks
+                ->dontRelease(),    // Don't re-queue on lock conflict
         ];
     }