[Performance] Memoize macAddress

[gonzaloriestra]

WHY are these changes introduced?

The macAddress function in packages/cli-kit performs a hardware lookup every time it's called. Since the MAC address of a machine doesn't change during the execution of a CLI process, we can memoize the result to avoid redundant expensive operations.

Expected performance impact: Reduces redundant I/O and CPU overhead from repeated MAC address lookups. Each lookup typically takes between 5ms and 20ms depending on the system.

WHAT is this pull request doing?

• Memoizes the result of macaddress.one() in packages/cli-kit/src/public/node/context/local.ts.
• Exports _resetMacAddressCache for test isolation.
• Updates unit tests to verify memoization and ensure clean state between tests.

How to test your changes?

CI

Post-release steps

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing — I've identified the correct bump type (patch for bug fixes · minor for new features · major for breaking changes) and added a changeset with pnpm changeset add

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PR created automatically by Jules for task 3263285904204586703 started by @gonzaloriestra

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[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

We found no new type declarations in this PR

Existing type declarations

packages/cli-kit/dist/public/node/crypto.d.ts

@@ -20,10 +20,10 @@ export declare function base64URLEncode(str: Buffer): string;
  */
 export declare function sha256(str: string): Buffer;
 /**
- * Generate the SHA1 hash of a string.
+ * Generate the SHA256 hash of a string.
  *
  * @param str - The string to hash.
- * @returns The SHA1 hash of the string.
+ * @returns The SHA256 hash of the string.
  */
 export declare function hashString(str: string): string;
 /**

packages/cli-kit/dist/public/node/context/local.d.ts

@@ -153,6 +153,10 @@ export declare function ciPlatform(env?: NodeJS.ProcessEnv): {
  * @returns Mac address.
  */
 export declare function macAddress(): Promise<string>;
+/**
+ * Resets the memoized mac address.
+ */
+export declare function _resetMacAddressCache(): void;
 /**
  * Get the domain for theme kit access.
  *