Add functionality to check for git extension updates, as well as support for installing a specific ref (#8018)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

packages/cli/src/commands/extensions/install.ts

@@ -15,6 +15,7 @@ import { getErrorMessage } from '../../utils/errors.js';
 interface InstallArgs {
   source?: string;
   path?: string;
+  ref?: string;
 }
 
 export async function handleInstall(args: InstallArgs) {
@@ -31,6 +32,7 @@ export async function handleInstall(args: InstallArgs) {
         installMetadata = {
           source,
           type: 'git',
+          ref: args.ref,
         };
       } else {
         throw new Error(`The source "${source}" is not a valid URL format.`);
@@ -66,7 +68,12 @@ export const installCommand: CommandModule = {
         describe: 'Path to a local extension directory.',
         type: 'string',
       })
+      .option('ref', {
+        describe: 'The git ref to install from.',
+        type: 'string',
+      })
       .conflicts('source', 'path')
+      .conflicts('path', 'ref')
       .check((argv) => {
         if (!argv.source && !argv.path) {
           throw new Error('Either source or --path must be provided.');
@@ -77,6 +84,7 @@ export const installCommand: CommandModule = {
     await handleInstall({
       source: argv['source'] as string | undefined,
       path: argv['path'] as string | undefined,
+      ref: argv['ref'] as string | undefined,
     });
   },
 };