* feat(cli): add fallback syntax option
Expose a new fallback syntax CLI option so users can opt into syntax highlighting only when auto-detection fails.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
* feat(syntax): apply fallback only after detection fails
Use the fallback syntax only when path and first-line detection fail, preserving existing behavior for detected files and explicit language selection.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
* test(cli): cover fallback syntax behavior
Add integration coverage for fallback syntax usage, precedence with --language, and no-op behavior when syntax is already detected; update help snapshots for the new option.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
* docs(changelog): document fallback syntax option
Record the new fallback syntax feature in the unreleased changelog section.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
---------
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>