Add global block type selection (Reject, Silence, Hang up)

[PS1Online]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

Add a global setting to choose how all blocked calls are handled,
regardless of the reason for blocking (anonymous numbers, numbers
not in contacts, spam, or manually blocked numbers).

The options should be:

• Reject — the call is rejected immediately, the caller hears a busy
  tone
• Silence — the call rings silently on the device, the caller hears
  a normal ring tone
• Hang up — the call is answered and immediately terminated, the
  caller hears nothing

Why do you want this feature?

Currently Fossify Phone applies a single fixed blocking behavior
(Reject) with no way to choose. Different users have different
preferences on how blocked calls should be handled.

From personal experience:

• Reject: the caller understands the call has been blocked, as it
  is rejected immediately. This is the default blocking behavior
  of any dialer app
• Silence: the caller does not realize the call has been blocked, as
  the call appears to ring normally
• Hang up: the caller perceives the number as dead — the call is
  disconnected immediately with no ring and no busy tone. This was
  also the default blocking behavior in the early 2000s

Apps like SpamBlocker (aj3423) already implement this choice via
the CallScreeningService API, proving it is feasible.

Additional information

Device: Honor 400
Android version: 16
ROM: MagicOS 10.0
Fossify Phone version: 1.11.1