Fix phone validation performance by using Set/Map instead of Array lookups (#17843)

## Summary
- **`isValidCountryCode`** was using `Array.includes()` on ~250 country
codes (O(n) per call). Replaced with a `Set.has()` lookup (O(1)).
- **`getCountryCodesForCallingCode`** was iterating all ~250 countries
and calling `getCountryCallingCode()` on each one **every invocation**.
Replaced with a precomputed `Map<callingCode, CountryCode[]>` built once
at module load (O(1) per call).

Both functions are called from `transformPhonesValue` on every phone
field mutation, causing cumulative overhead visible in profiling (p95
self-time ~20-35ms).

## Test plan
- [ ] Verify phone field creation/update still works correctly (country
code validation, calling code resolution)
- [ ] Verify spreadsheet import with phone fields still validates
properly
- [ ] Confirm no regression in `isValidCountryCode` or
`getCountryCodesForCallingCode` behavior


Made with [Cursor](https://cursor.com)

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/twenty-shared/src/utils/validation/phones-value/getCountryCodesForCallingCode.ts

@@ -1,15 +1,30 @@
-import { getCountries, getCountryCallingCode } from 'libphonenumber-js';
+import {
+  type CountryCode,
+  getCountries,
+  getCountryCallingCode,
+} from 'libphonenumber-js';
 
-const ALL_COUNTRIES_CODE = getCountries();
+// Precompute a map from calling code to country codes for O(1) lookups
+const CALLING_CODE_TO_COUNTRIES = new Map<string, CountryCode[]>();
 
-export const getCountryCodesForCallingCode = (callingCode: string) => {
+for (const country of getCountries()) {
+  const callingCode = getCountryCallingCode(country);
+
+  const existing = CALLING_CODE_TO_COUNTRIES.get(callingCode);
+
+  if (existing) {
+    existing.push(country);
+  } else {
+    CALLING_CODE_TO_COUNTRIES.set(callingCode, [country]);
+  }
+}
+
+export const getCountryCodesForCallingCode = (
+  callingCode: string,
+): CountryCode[] => {
   const cleanCallingCode = callingCode.startsWith('+')
     ? callingCode.slice(1)
     : callingCode;
 
-  return ALL_COUNTRIES_CODE.filter((country) => {
-    const countryCallingCode = getCountryCallingCode(country);
-
-    return countryCallingCode === cleanCallingCode;
-  });
+  return CALLING_CODE_TO_COUNTRIES.get(cleanCallingCode) ?? [];
 };

packages/twenty-shared/src/utils/validation/phones-value/isValidCountryCode.ts

@@ -1,7 +1,7 @@
 import { type CountryCode, getCountries } from 'libphonenumber-js';
 
-const ALL_COUNTRIES_CODE = getCountries();
+const ALL_COUNTRIES_CODE_SET = new Set<string>(getCountries());
 
 export const isValidCountryCode = (input: string): input is CountryCode => {
-  return ALL_COUNTRIES_CODE.includes(input as unknown as CountryCode);
+  return ALL_COUNTRIES_CODE_SET.has(input);
 };