Tina: Code injection via unescaped Git branch name in generated client source

Tina is a headless content management system. Prior to 3.0.0, @tinacms/cli reads Git branch values from VERCEL_GIT_COMMIT_REF, GITHUB_BRANCH, or HEAD, incorporates the raw value into the API URL, and interpolates that URL into JavaScript string literals in packages/@tinacms/cli/src/next/codegen/index.ts and packages/@tinacms/cli/src/next/codegen/codegen/plugin.ts. A crafted Git-valid branch name containing a quote can terminate the generated string and inject an expression that executes when the generated client module is imported during a preview build. The injected code runs with the build process privileges and can read environment credentials, modify deployment artifacts, or make network requests. This issue is fixed in version 3.0.0.