Implement createBranch, add page param to listBranches, rewrite pagination test

- Implement createBranch using GitHub refs API
- Add page parameter to listBranches for consistency with other methods
- Rewrite testListBranchesFetchesMultiplePages to use a real created repository
  with actual branches instead of a hardcoded external repo

Author: HarshMN2345

src/VCS/Adapter/Git/GitHub.php

@@ -181,7 +181,15 @@ public function createFile(string $owner, string $repositoryName, string $filepa
      */
     public function createBranch(string $owner, string $repositoryName, string $newBranchName, string $oldBranchName): array
     {
-        throw new Exception("Not implemented");
+        $latestCommit = $this->getLatestCommit($owner, $repositoryName, $oldBranchName);
+        $sha = $latestCommit['commitHash'];
+
+        $response = $this->call(self::METHOD_POST, "/repos/$owner/$repositoryName/git/refs", ['Authorization' => "Bearer $this->accessToken"], [
+            'ref' => "refs/heads/$newBranchName",
+            'sha' => $sha,
+        ]);
+
+        return $response['body'] ?? [];
     }
 
     /**
@@ -739,13 +747,13 @@ public function getPullRequestFromBranch(string $owner, string $repositoryName,
      * @param  string  $owner Owner name of the repository
      * @param  string  $repositoryName Name of the GitHub repository
      * @param  int  $perPage Number of branches to fetch per page
+     * @param  int  $page Page number to start fetching from
      * @return array<string> List of branch names as array
      */
-    public function listBranches(string $owner, string $repositoryName, int $perPage = 100): array
+    public function listBranches(string $owner, string $repositoryName, int $perPage = 100, int $page = 1): array
     {
         $url = "/repos/$owner/$repositoryName/branches";
         $perPage = min(max($perPage, 1), 100);
-        $page = 1;
         $names = [];
 
         do {

tests/VCS/Adapter/GitHubTest.php

@@ -527,15 +527,25 @@ public function testGetCommitWithInvalidHash(): void
 
     public function testListBranchesFetchesMultiplePages(): void
     {
-        $this->assertInstanceOf(GitHub::class, $this->vcsAdapter);
+        $repositoryName = 'test-list-branches-pages-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
 
-        /** @var GitHub $adapter */
-        $adapter = $this->vcsAdapter;
-        $branches = $adapter->listBranches('test-kh', 'test1', 1);
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'branch-a', static::$defaultBranch);
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'branch-b', static::$defaultBranch);
 
-        $this->assertIsArray($branches);
-        $this->assertContains('main', $branches);
-        $this->assertContains('test', $branches);
+            /** @var GitHub $adapter */
+            $adapter = $this->vcsAdapter;
+            $branches = $adapter->listBranches(static::$owner, $repositoryName, 1);
+
+            $this->assertIsArray($branches);
+            $this->assertContains(static::$defaultBranch, $branches);
+            $this->assertContains('branch-a', $branches);
+            $this->assertContains('branch-b', $branches);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testGetLatestCommit(): void