Method change

backend/src/git/core/mod.rs:193–199

(&self, id: &ExternalId)

    }

    pub fn change(&self, id: &ExternalId) -> Result<activity::Change> {
        let result = self.find_blob_by_filename(&id.change_filename()?)?;
        match result {
            Some(blob) => Ok(blob.try_into()?),
            None => Err(Error::NotFound(format!("not found: {id}"))),
        }
    }

    pub fn duplicate(&self) -> Result<Self> {
        Ok(Self {