Phone number validation does not support Bangladesh country code (+88)

[jorikfon]

Bug Description

When trying to add a Bangladesh phone number with country code +88 (e.g., +8801767820010) to an extension user, the system does not accept the number.

Expected Behavior

• The system should accept valid Bangladesh phone numbers starting with +88
• Phone number +8801767820010 should be accepted as a valid number

Current Behavior

• The system rejects Bangladesh phone numbers with country code +88
• Unable to save extension user with Bangladesh phone numbers

Steps to Reproduce

1. Go to Extension User configuration
2. Try to add a phone number: +8801767820010
3. System rejects the phone number

Technical Details

• Country Code: +88 (Bangladesh)
• Number Format: +88017XXXXXXXX
• Example Number: +8801767820010

Additional Information

Bangladesh mobile numbers follow the format:

• Country code: +88
• Operator code: 017 (in this case)
• Subscriber number: XXXXXXXX (8 digits)

Environment

• MIKOPBX Core Version: [Please specify your version]

Suggested Fix

Update the phone number validation rules to include Bangladesh country code (+88) and number format pattern.

Impact

This issue affects users trying to configure extensions with Bangladesh phone numbers, limiting the PBX's usability in Bangladesh region.