build: Switch from Yarn to pnpm

.github/workflows/publish.yml

@@ -37,14 +37,17 @@ jobs:
         with:
           persist-credentials: false
 
+      - name: Setup pnpm
+        uses: pnpm/action-setup@ea17c68df8912ef543352723c149a84f56e3d413 # v6.1.0
+
       - name: Setup Node
         uses: actions/setup-node@v6
         with:
           node-version: 24
-          cache: yarn
+          cache: pnpm
 
-      - name: Install yarn dependencies
-        run: yarn install --frozen-lockfile
+      - name: Install pnpm dependencies
+        run: pnpm install --frozen-lockfile
 
       - name: Parse target repository
         id: target
@@ -220,15 +223,20 @@ jobs:
         with:
           path: .__publish__
 
+      - name: Setup pnpm
+        uses: pnpm/action-setup@ea17c68df8912ef543352723c149a84f56e3d413 # v6.1.0
+        with:
+          package_json_file: .__publish__/package.json
+
       - name: Setup Node
         uses: actions/setup-node@v6
         with:
           node-version: 24
-          cache: yarn
-          cache-dependency-path: .__publish__/yarn.lock
+          cache: pnpm
+          cache-dependency-path: .__publish__/pnpm-lock.yaml
 
-      - name: Install yarn dependencies
-        run: yarn install --cwd ".__publish__"
+      - name: Install pnpm dependencies
+        run: pnpm --dir .__publish__ install --frozen-lockfile
 
       - name: Parse and set inputs
         id: inputs

.github/workflows/test.yml

@@ -17,18 +17,14 @@ jobs:
     name: unit tests
     steps:
       - uses: actions/checkout@v6
+      - uses: pnpm/action-setup@ea17c68df8912ef543352723c149a84f56e3d413 # v6.1.0
       - uses: actions/setup-node@v6
         with:
           node-version: 24
-      - uses: actions/cache@v4
-        id: cache
-        with:
-          path: node_modules
-          key: ${{ runner.os }}-node_modules-${{ hashFiles('package.json', 'yarn.lock') }}
+          cache: pnpm
 
       - name: Install Dependencies
-        if: steps.cache.outputs.cache-hit != 'true'
-        run: yarn install --frozen-lockfile
+        run: pnpm install --frozen-lockfile
 
       - name: Test
-        run: yarn test
+        run: pnpm test

.prettierignore

@@ -0,0 +1 @@
+pnpm-lock.yaml

AGENTS.md

@@ -10,45 +10,45 @@ This is the **Sentry Publish Repository** - a GitHub Actions-based approval syst
 
 ### Package Manager
 
-- **Yarn 1.22.22** (classic) - Do NOT use npm
-- Version management via Volta (pinned in package.json)
+- **pnpm 12.8.1** (pinned in package.json) - Do NOT use yarn or npm
+- Node.js version management via Volta (pinned in package.json)
 
 ### Commands
 
 ```bash
 # Install dependencies
-yarn install
+pnpm install --frozen-lockfile
 
 # Run all tests
-yarn test
+pnpm test
 
 # Run tests in watch mode
-yarn test:watch
+pnpm test:watch
 
 # Run a single test file
-yarn test src/modules/__tests__/update-issue.js
+pnpm test src/modules/__tests__/update-issue.js
 
 # Run tests matching a pattern
-yarn test -t "pattern"
+pnpm test -t "pattern"
 
 # Lint code
-yarn lint
+pnpm lint
 
 # Format code with Prettier
-yarn prettier
+pnpm prettier
 ```
 
 ### Running Single Tests
 
 ```bash
 # By file path
-yarn test src/modules/__tests__/update-issue.js
+pnpm test src/modules/__tests__/update-issue.js
 
 # By test name pattern (matches describe/test names)
-yarn test -t "transformIssueBody"
+pnpm test -t "transformIssueBody"
 
 # Combine file and pattern
-yarn test src/modules/__tests__/update-issue.js -t "specific test name"
+pnpm test src/modules/__tests__/update-issue.js -t "specific test name"
 ```
 
 ## Project Structure
@@ -121,7 +121,7 @@ module.exports = functionName;
 - **Prettier** with default settings
 - Double quotes for strings
 - Semicolons required
-- Run `yarn prettier` before committing
+- Run `pnpm prettier` before committing
 
 ## Error Handling
 
@@ -273,3 +273,9 @@ This codebase interacts heavily with GitHub Actions. Entry points in `src/publis
 ## Code Owners
 
 All code is owned by `@getsentry/releng` (Release Engineering team).
+
+<!-- This section is maintained by the coding agent via lore (https://github.com/BYK/loreai) -->
+## Long-term Knowledge
+
+For long-term knowledge entries managed by [lore](https://github.com/BYK/loreai) (gotchas, patterns, decisions, architecture), see [`.lore.md`](.lore.md) in the project root.
+<!-- End lore-managed section -->

README.md

@@ -6,6 +6,9 @@ This is a meta/control repository that implements the [Central Publish Repositor
 
 [craft quick start](https://craft.sentry.dev/github-actions/)
 
+For local development, use Node.js 24 and pnpm 12.8.1. Run `pnpm install --frozen-lockfile`,
+then `pnpm test` and `pnpm lint`. CI installs dependencies from `pnpm-lock.yaml`.
+
 ## Release Flow
 
 ```mermaid

package.json

@@ -8,16 +8,13 @@
   "author": "Sentry Open Source <oss@sentry.io>",
   "license": "Apache-2.0",
   "volta": {
-    "node": "24.0.0",
-    "yarn": "1.22.22"
-  },
-  "resolutions": {
-    "undici": "^6.23.0"
+    "node": "24.0.0"
   },
+  "packageManager": "pnpm@12.8.1",
   "scripts": {
     "generate": "node scripts/generate-publish-issue-title-parser.js",
     "check:generated": "node scripts/generate-publish-issue-title-parser.js --check",
-    "test": "yarn check:generated && vitest run",
+    "test": "pnpm run check:generated && vitest run",
     "test:watch": "vitest",
     "lint": "eslint src .github --ignore-pattern '!.github'",
     "prettier": "prettier --write src"