Fix encrypt/decrypt crash when .gitignore is missing

[Copilot]

fsr encryption (and the encrypt/decrypt flows it drives) crashed whenever the project had no .gitignore file: utils.readFile returned {} on read error, so encryption.js died at encrypted.ignore.split("\n") with TypeError: encrypted.ignore.split is not a function — nothing got encrypted or decrypted.

Changes

• lib/utils/helpers.js — readFile now returns "" (a safe string default) on error instead of {}, and uses the async fs.readFile instead of readFileSync:

utils.readFile = async f => {
    try {
        return await fs.readFile(f, "utf8");
    } catch (err) {
        fsrLog.error(err);
        return ""; // was: {} — broke string callers like encryption.js
    }
};

• tests/utils/helpers.test.js — updated the missing-file expectation from {} to "".
• tests/encryption/encryption.test.js — regression test: init() encrypts listed files when .gitignore is missing.