Get branch diff

GET /api/v1/repos/branches/diff?branch=BRANCH_NAME&base=BASE_BRANCH&ephemeral=true&ephemeral_base=false&path=src/main.go&path=README.md
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{
  "branch": "feature/new-feature",
  "base": "main",
  "stats": {
    "files": 5,
    "additions": 120,
    "deletions": 30,
    "changes": 150
  },
  "files": [
    {
      "path": "src/feature.go",
      "state": "A",
      "old_path": "",
      "bytes": 2048,
      "is_eof": true,
      "raw": "diff --git a/src/feature.go b/src/feature.go\nnew file mode 100644\nindex 0000000..abc123\n--- /dev/null\n+++ b/src/feature.go\n@@ -0,0 +1,50 @@\n+package main\n+\n+func NewFeature() {\n+    // Implementation\n+}\n"
    },
    {
      "path": "src/main.go",
      "state": "M",
      "old_path": "",
      "bytes": 1024,
      "is_eof": true,
      "raw": "diff --git a/src/main.go b/src/main.go\nindex abc123..def456 100644\n--- a/src/main.go\n+++ b/src/main.go\n@@ -10,6 +10,8 @@\n+    feature := NewFeature()\n+    feature.Run()\n"
    }
  ],
  "filtered_files": [
    {
      "path": "go.sum",
      "state": "M",
      "old_path": "",
      "bytes": 50000,
      "is_eof": true
    }
  ]
}