Replace fs-extra calls with native equivalent

[troyciesco]

fs-extra can be fully replaced with native Node.js APIs.

Below is a quick pass at finding the usage and what needs to be replaced (may be incomplete):

Methods used

Method	Uses	Native replacement	Drop-in?
readdir()	3	fs/promises.readdir()	Yes
readFile()	2	fs/promises.readFile()	Yes
remove()	6	fs/promises.rm(path, {recursive: true, force: true})	Yes
pathExists()	5	fs/promises.access() wrapped in try/catch	No — needs helper or inline try/catch

Files to update

lib/read-theme.js

• readdir() — drop-in
• readFile() — drop-in
• remove() — replace with fs/promises.rm(path, {recursive: true, force: true})

lib/checker.js

• remove() — replace with fs/promises.rm(path, {recursive: true, force: true})

app/index.js

• remove() — replace with fs/promises.rm(path, {recursive: true, force: true})

test/general.test.js

• readdir() — drop-in
• pathExists() — replace with fs/promises.access() + try/catch
• remove() — replace with fs/promises.rm(path, {recursive: true, force: true})

test/read-zip.test.js

• pathExists() — replace with fs/promises.access() + try/catch
• remove() — replace with fs/promises.rm(path, {recursive: true, force: true})

test/read-theme.test.js

• readdir() — mocked via vi.spyOn, update spy target to fs/promises
• readFile() — mocked via vi.spyOn, update spy target to fs/promises

pathExists() replacement

fs-extra's pathExists() has no direct native equivalent. Options:

// Option A: inline
async function pathExists(p) {
    try {
        await fs.access(p);
        return true;
    } catch {
        return false;
    }
}

// Option B: just use access() directly and catch where needed

After migration

• Remove fs-extra from package.json dependencies
• Replace all require('fs-extra') with require('fs/promises') (or require('fs') where sync methods are needed)