feat(isMobilePhone): Add Monaco mobile phone numbers support

[tonienguix]

feat(isMobilePhone): Add Monaco mobile phone numbers support

Added one line of code to provide support for Monaco prefixes:

'fr-MC': /^(\+?377)(4[456]\d{6}|6\d{8})$/,

The regex is based on this reference https://en.wikipedia.org/wiki/Telephone_numbers_in_Monaco

Checklist

• PR contains only changes related; no stray files, etc.
• README updated (where applicable)
• Tests written (where applicable)
• References provided in PR (where applicable)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (7a80797) to head (3558bee).

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #2697   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files          114       114           
  Lines         2586      2586           
  Branches       656       656           
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  Hits          2586      2586           

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[Copilot]

Pull request overview

Adds a new isMobilePhone locale to support Monaco (fr-MC) phone number validation, including documentation and tests, aligning with the project’s locale-driven regex approach.

Changes:

• Added fr-MC regex to src/lib/isMobilePhone.js.
• Added fr-MC fixtures to the isMobilePhone validator test suite.
• Documented fr-MC in the README’s isMobilePhone locale list.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/lib/isMobilePhone.js	Adds fr-MC locale regex to the phones map.
test/validators.test.js	Adds fr-MC valid/invalid fixtures to the isMobilePhone test matrix.
README.md	Includes fr-MC in the documented locale list for isMobilePhone.

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[Copilot]

The fr-MC pattern mixes different national-number lengths: the 4[456]\d{6} branch matches 8 digits after 377, but the 6\d{8} branch matches 9 digits after 377. This inconsistency is likely unintended and will accept numbers with different lengths depending on prefix. Please verify Monaco’s mobile number length and adjust the regex (and corresponding fixtures) so both branches reflect the correct national significant number length.

Suggested change

	'fr-MC': /^(\+?377)(4[456]\d{6}|6\d{8})$/,
	'fr-MC': /^(\+?377)(4[456]\d{6}|6\d{7})$/,

[Copilot]

The added fr-MC fixtures treat +3776… numbers as having 9 digits after the country code (e.g. +377612345678), while +37744… numbers have 8 digits after the country code. This makes the fixture set internally inconsistent and tightly couples it to the current regex behavior. After confirming the correct Monaco number length, please update these test cases to use the correct digit count consistently.

Suggested change

	'+377612345678',
	'+377698765432',
	'37744123456',
	'37745678901',
	'37746234567',
	'377612345678',
	'377698765432',
	],
	invalid: [
	'37743123456',
	'+37747123456',
	'+37741123456',
	'+377512345678',
	'+37761234567',
	'+37769876543',
	'37744123456',
	'37745678901',
	'37746234567',
	'37761234567',
	'37769876543',
	],
	invalid: [
	'37743123456',
	'+37747123456',
	'+37741123456',
	'+377612345678',