pnpm corepack, CI bugfix and no warnings for TIMEID

README.md

@@ -67,7 +67,7 @@ change the setting.
 ### Retrofitting existing notes
 
 Notes created before you adopted this workflow have no TIMEID. Right-click such a note in the
-file explorer and choose **"Add zettel TIMEID to filename"**. It mints a fresh timestamp,
+file explorer and choose **"Prefix timestamp to filename"**. It mints a fresh timestamp,
 prepends it, and the note is now a zettel that syncs on future H1 edits.
 
 ## Pretty sidebar (optional)
@@ -89,14 +89,43 @@ are fixed.
 
 ## Development
 
-- `npm install` (or `pnpm install`).
-- `npm run dev` - compile in watch mode.
-- `npm run build` - typecheck and produce `main.js`.
-- `npm test` - run the slug unit tests on Node's built-in test runner.
-- `npm run lint` - eslint with the Obsidian ruleset.
+Dependencies are managed with **pnpm** (see "Why pnpm, not npm" below). Node 22+ ships
+`corepack`, so you do not need to install pnpm globally, and the `packageManager` field in
+`package.json` pins the exact version.
+
+```bash
+corepack pnpm install     # first time, or after a dependency change
+corepack pnpm run dev     # compile in watch mode
+corepack pnpm run build   # typecheck and produce main.js
+corepack pnpm test        # run the slug unit tests (Node's built-in runner)
+corepack pnpm run lint    # eslint with the Obsidian ruleset
+```
 
 The pure string logic lives in `src/slug.ts` and is unit-tested in isolation; the Obsidian
-wiring lives in `src/main.ts`.
+wiring lives in `src/main.ts`. Tests run on Node's built-in test runner (`node --test`) - there
+is no vitest or jest dependency.
+
+### Why pnpm, not npm
+
+**Do not run `npm install` or `npm ci` in this repo.** This project is developed on a **ZFS**
+filesystem, and npm's installer renames many directories in parallel (to hoist and dedupe
+packages). That races ZFS's directory-metadata handling and aborts with:
+
+```
+npm error code ENOTEMPTY
+npm error syscall rename
+```
+
+pnpm avoids the problem entirely: it hard-links packages from a global content-addressable
+store instead of renaming directories into place, so it installs cleanly on the same disk.
+
+Notes for contributors:
+
+- Only `npm install` / `npm ci` are affected. Running *scripts* through npm (`npm run build`)
+  still works, because that just spawns tsc/esbuild and installs nothing. Still, prefer `pnpm`
+  everywhere for consistency.
+- The lockfile is `pnpm-lock.yaml` (committed). There is no `package-lock.json`; do not create
+  one.
 
 ## License