How would I integrate with issue tracking tools? (Mantis or Jira)
Jira expose all its features through API and also has client libraries to interact with these APIs. but JIRA recommends to use API directly instead.
You can all the APIs from your listener classes in Testng or anyother framework you are using
A member of the team suggested using Python with Selenium Webdriver, is it interesting? (I am afraid)
There is no dependency between backend code and the tool used for test automation. Test automation tools like protractor ,playwright etc have inbuild handling of angular asynchronous nature so could be used for angular projects. Meaning you can use it without need of adding any additional explicit or implicit wait ( meaning you don't have to write code to ensure element is present in the page before doing some action )
Also if there is no contribution from dev team in test automation , you don't have to worry about what language they are comfortable with.
How selenium works:
Below is the architecture of selenium. The actual functionality is handled by driver, eg : chromedriver. It has programs to talk to browser and make it do things and get information from browser
These functions in chrome driver are exposed through an API so that client can have access to these function by just calling this APIs
selenium python , java etc are libraries that have code to interact with this API.
So the language binding you use have no effect on your automation. Use the language you and your team comfortable in
When developers make commits to the QA environment, how would I go about doing automated testing automatically? (CI)
How are the deployment happens in the organisation use the same tool or use windows schedule task
You can also install local jenkins/azure/octopus or any other CI/CD