fix(cli): add +91 prefix automatically for login

Description

Problem

The CLI login flow required users to manually include the +91 country code while entering their mobile number.

However, in the GUI application, the +91 prefix is automatically added on the client side.

This mismatch caused:

• Login failures for CLI users
• Confusion for users familiar with the GUI

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Solution

Updated the CLI login implementation to normalize phone number input:

• Accepts 10-digit mobile numbers from users
• Automatically prepends +91 if the prefix is missing

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Before vs After

Scenario	Before	After
User Input	9876543210	9876543210
Sent to API	9876543210	+919876543210
Result	Login failed	Login success

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Changes Made

• Updated input label:
  Phone number → Phone number (+91)
• Added logic to prepend +91 if not already present
• Ensured compatibility for numbers already containing +91

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Impact

• Aligns CLI behavior with GUI
• Improves user experience
• Prevents login failures due to format mismatch

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Testing

Test Cases:

1. Input: 9876543210

   • Expected: +919876543210 sent to API

2. Input: +919876543210

   • Expected: remains unchanged