feat(uncheck): add uncheck init to set up a project

packages/uncheck/README.md

@@ -24,15 +24,15 @@
 `uncheck` lints, format checks and type checks your project with one command, and keeps a monorepo consistent. It runs the tools your project already has, so you, your git hooks and your coding agents all run the same check.
 
 ```sh
-npm i -D uncheck oxlint oxfmt typescript   # add sherif in a monorepo
+npx uncheck init                   # install the tools, add the scripts and hooks
 
 npx uncheck                        # check everything
 npx uncheck --fix                  # fix what can be fixed, report the rest
 npx uncheck prepare --pre-commit   # check every commit
 npx uncheck hooks install claude   # check every agent turn
 ```
 
-uncheck needs Node 22.20 or later. Install only the tools you want: a check runs when its tool is installed and is skipped otherwise, except that a `tsconfig.json` without TypeScript installed fails. uncheck always uses the versions you installed.
+uncheck needs Node 22.20 or later. Install only the tools you want, with [`init`](#set-up-a-project) or by hand (`npm i -D uncheck oxlint oxfmt typescript`, plus sherif in a monorepo): a check runs when its tool is installed and is skipped otherwise, except that a `tsconfig.json` without TypeScript installed fails. uncheck always uses the versions you installed.
 
 | Check    | Checks               | Runs when                                                                                          |
 | -------- | -------------------- | -------------------------------------------------------------------------------------------------- |
@@ -41,6 +41,25 @@ uncheck needs Node 22.20 or later. Install only the tools you want: a check runs
 | `oxfmt`  | formatting           | [oxfmt](https://oxc.rs) is installed                                                               |
 | `tsc`    | types                | the project has a `tsconfig.json`                                                                  |
 
+## Set up a project
+
+```sh
+npx uncheck init   # or pnpm dlx, yarn dlx, bunx
+```
+
+`init` sets up the folder it runs in, a new project or an existing one, and installs with the package manager the project uses: the one its `packageManager` field or lockfile names, or else the one that started `init`. It asks:
+
+1. **Which tools to install:** oxlint and oxfmt, plus sherif at a [workspace root](#monorepos). uncheck itself is always installed.
+2. **Which tools get a preset config:** oxlint and oxfmt can start from the [presets](#presets) when they have no config yet.
+3. **Whether to check every commit:** it adds the [`prepare` script](#run-it-before-every-commit) (`postinstall` with Yarn 2+) and writes the hook.
+4. **Which agents run uncheck** [after every turn](#run-it-after-every-agent-turn).
+
+It also adds a `check` script (`uncheck`) and a `fix` script (`uncheck --fix`), unless the project has scripts with those names. Running `init` again only sets up what is missing. A `prepare` script that already runs `uncheck prepare` keeps its hook, and agents that already run uncheck keep their flags: change those in the `prepare` script or with `uncheck hooks install`.
+
+`npx uncheck init --yes` takes the default answers, which it needs without a terminal. It installs the missing tools, checks every commit, and sets up the agents whose folders the project has, such as `.claude`, that do not run uncheck yet. It writes no preset config.
+
+In a monorepo, run `init` at the workspace root to set up every package at once. TypeScript is left to you: tsc runs once the project has a `tsconfig.json` and TypeScript is installed.
+
 ## Check your project
 
 ```text

packages/uncheck/src/checks/sherif.ts

@@ -1,22 +1,18 @@
 import process from 'node:process'
 
-import { Effect, FileSystem, Path, Predicate } from 'effect'
+import { Effect, Path, Predicate } from 'effect'
 
 import { CannotCheck, NothingToCheck } from '../errors'
-import { readJson } from '../files'
+import { isWorkspaceRoot, readJson } from '../files'
 import { resolveBin } from '../tool'
 import type { Check } from '../types'
 
 const WORKSPACE_FILES = new Set(['package.json', 'pnpm-workspace.yaml'])
 
-// pnpm also keeps its settings in pnpm-workspace.yaml, and sherif fails on one without packages.
-const DECLARES_PACKAGES = /^["']?packages["']?\s*:/m
-
 export const sherif: Check = {
   name: 'sherif',
   fixes: 'workspace',
   plan: Effect.fn(function* ({ cwd, fix, files, deleted }) {
-    const fs = yield* FileSystem.FileSystem
     const path = yield* Path.Path
 
     const bin = yield* resolveBin('sherif', cwd)
@@ -34,22 +30,13 @@ export const sherif: Check = {
       )
     }
 
-    const [manifest, pnpmWorkspace] = yield* Effect.all(
-      [
-        readJson(path.join(cwd, 'package.json')),
-        fs.readFileString(path.join(cwd, 'pnpm-workspace.yaml')).pipe(
-          Effect.map((text) => DECLARES_PACKAGES.test(text)),
-          Effect.orElseSucceed(() => false),
-        ),
-      ],
-      { concurrency: 'unbounded' },
-    )
+    const manifest = yield* readJson(path.join(cwd, 'package.json'))
 
     if (manifest === undefined) {
       return yield* Effect.fail(new NothingToCheck({ reason: 'no package.json found' }))
     }
 
-    if (manifest.workspaces === undefined && !pnpmWorkspace) {
+    if (!(yield* isWorkspaceRoot(cwd, manifest))) {
       return yield* Effect.fail(new NothingToCheck({ reason: 'not a workspace root' }))
     }
 

packages/uncheck/src/checks/tsc.ts

@@ -7,6 +7,7 @@ import { CannotCheck, NothingToCheck } from '../errors'
 import {
   ancestors,
   fileKind,
+  firstFile,
   isOutside,
   listProjectFiles,
   readJson,
@@ -813,11 +814,6 @@ const loadExtendsChain = Effect.fn(function* (
   return [...chains.flat(), { file: configPath, dir: path.dirname(configPath), raw }]
 })
 
-const firstFile = (candidates: ReadonlyArray<string>) =>
-  Effect.findFirst(candidates, (candidate) =>
-    Effect.map(fileKind(candidate), (type) => type === 'File'),
-  )
-
 const resolveExtends = Effect.fn(function* (spec: string, dir: string) {
   const path = yield* Path.Path
 

packages/uncheck/src/cli.ts

@@ -7,6 +7,7 @@ import { CliConfig, CliError, CliOutput, Command, GlobalFlag } from 'effect/unst
 
 import pkg from '../package.json'
 import { hooks } from './commands/hooks'
+import { init } from './commands/init'
 import { prepare } from './commands/prepare'
 import { staged } from './commands/staged'
 import { uncheck } from './commands/uncheck'
@@ -21,7 +22,7 @@ for (const stream of [process.stdout, process.stderr]) {
 // (the shell forwards it, then the kernel), so `once` is not enough.
 process.on('SIGHUP', () => process.kill(process.pid, 'SIGTERM'))
 
-Command.run(uncheck.pipe(Command.withSubcommands([staged, prepare, hooks])), {
+Command.run(uncheck.pipe(Command.withSubcommands([init, staged, prepare, hooks])), {
   version: pkg.version,
 }).pipe(
   Effect.catchTag('CheckFailed', () =>