Normalize exception handling in command classes

[dereuromark]

Summary

Normalizes exception handling patterns across command classes for consistency.

Changes

MigrateCommand & RollbackCommand

• Remove redundant catch (Exception $e) block since catch (Throwable $e) already covers all exceptions
• Remove unused use Exception; import

SeedCommand

• Change from catch (Exception $e) to catch (Throwable $e) for consistency
• Use $io->err('<error>...</error>') instead of $io->error() to match other commands
• Add $io->verbose($e->getTraceAsString()) for debugging consistency

Before/After

Before (MigrateCommand/RollbackCommand):

} catch (Exception $e) {
    $io->err('<error>' . $e->getMessage() . '</error>');
    $io->verbose($e->getTraceAsString());
    return self::CODE_ERROR;
} catch (Throwable $e) {
    $io->err('<error>' . $e->getMessage() . '</error>');
    $io->verbose($e->getTraceAsString());
    return self::CODE_ERROR;
}

After:

} catch (Throwable $e) {
    $io->err('<error>' . $e->getMessage() . '</error>');
    $io->verbose($e->getTraceAsString());
    return self::CODE_ERROR;
}

Test plan

• phpcs passes
• phpstan passes
• Existing tests pass