[1.0.x] Neon CRM events

Hi, thanks for submitting this module

I went through the code, plus ran phpcs/phpstan/phpunit and wanted to share what I found so you can get this over the line.
Nothing here is scary, and most of it is quick to fix.
Two things below I'd consider must-fix, the rest is smaller polish.

1. A permission that isn't actually enforced (please fix)
You've defined a `sync neon crm events` permission, but it's never checked in the code not in the submit handler, not on the route.
Right now anyone who can edit one of these nodes can trigger a sync, whether or not they have that permission.
I'm guessing this was meant to gate the "Sync from Neon" button could you add a check for it in `syncSubmit()` (or drop the permission if it's not needed)?

2. The API key is stored/shown as plain text (please fix)
In the settings form, the API key field uses a regular textfield, so it prints back out in plain text every time someone opens the settings page, and it sits unmasked in any config export or backup.
Could you switch that field to `#type: password`? Long term, pointing people at the `key` module for storing this kind of credential would be even nicer, but the password field alone solves the immediate exposure.

3. Small coding standards cleanup
phpcs flagged 10 spots in `NeonCrmEventsHooks.php` where `t()` is called directly instead of `$this->t()` all inside the `help()` and `formNodeFormAlter()` methods. Adding `use StringTranslationTrait` to the class and swapping those calls over will clear it up. (The `t()` calls in the static submit/ajax methods are fine as they are you can't use `$this->t()` there anyway, and phpcs correctly leaves those alone.)

4. A few phpstan notes in `NeonCrmApi.php`
- Line 179: the `is_array($data)` check is redundant at that point you've already confirmed it's an array a few lines up.
- Line 282: `isset($m[3])` will always be true there, since the regex's AM/PM group is required and PCRE fills in the earlier optional group once a later one matches. `(int) $m[3]` on its own is enough.
- Line 366: `filter_default_format()` is deprecated as of 11.4 and goes away in 13.0 worth switching to the `FilterFormatRepositoryInterface` service now rather than later.

5. README is a little out of date
The "File structure" section still mentions a `.install` file, a `Service/` folder, and a `templates/` folder that aren't there anymore (the module's moved to `src/Hook/` and config-based install). Just needs a quick pass to match what's actually in the repo.

6. No tests yet
Not a blocker for the application, but a couple of unit tests around `combineDateTime()` and `extractEventId()` would be a nice addition given they're doing regex parsing.

Let me know if anything above is unclear or you'd like a hand with any of it!

Thank you for applying!

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FILE: src/NeonCrmApi.php

  /**
   * The config factory.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected $configFactory;

  /**
   * The HTTP client.
   *
   * @var \GuzzleHttp\ClientInterface
   */
  protected $httpClient;

  /**
   * The logger channel.
   *
   * @var \Drupal\Core\Logger\LoggerChannelInterface
   */
  protected $logger;

  /**
   * Constructs a new NeonCrmApi.
   *
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory.
   * @param \GuzzleHttp\ClientInterface $http_client
   *   The HTTP client.
   * @param \Drupal\Core\Logger\LoggerChannelFactoryInterface $logger_factory
   *   The logger channel factory.
   */
  public function __construct(
    ConfigFactoryInterface $config_factory,
    ClientInterface $http_client,
    LoggerChannelFactoryInterface $logger_factory,
  ) {
    $this->configFactory = $config_factory;
    $this->httpClient = $http_client;
    $this->logger = $logger_factory->get('neon_crm_events');
  }

Modules which are compatible with Drupal 10 and higher versions are expected to use constructor property promotion.

I am not sure that using a password form element for a key value is the correct way to go, for two reasons:

• When a password form element is used for an account password, it is used for a value that is supposedly changed by a single person (the person who created the account). The settings for a module could be changed by more than one person, if the site is not personal.
• To change an account password, it is necessary to first enter the current password. Without asking first the old value, somebody who gained access to an account which can change those settings could change the key value without knowing the value of the key.

To avoid somebody who gains access to an account with elevated permissions changes the key, the solution could be doing like Drupal core does some values: retrieve those values using the Drupal\Core\Site\Settings class.

A password form element is thought for a value (the password) that is changed by a single person. Even in that case, to change a password, the previous value must be entered.
That does work well for a value that can be changed by two or more people. In that case, how can a person visiting the form know the value has been already changed by another person? Should that person try changing the key?

Still, how can a person who has access to that form know the API key has been already updated from somebody else, in a different moment?