chore: migrate from Yarn to PNPM

[daniel-graham-amplitude]

Summary

We're migrating from Yarn to PNPM to take advantage of performance and security enhancements that PNPM provides. And because Yarn v1 has been in maintenance mode for ~6 years

Made a test pre-release called @amplitude/[email protected] and tested it locally

Checklist

• Does your PR title have the correct title format?
• Does your PR have a breaking change?: No

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Note

Migrates the build system to pnpm and aligns CI, publishing, and docs accordingly, with minor code/test adjustments for compatibility.

• Switches all GitHub Actions, composite actions, and Husky hooks from yarn to pnpm, adds pnpm/action-setup and enables setup-node@v4 caching
• Updates root package.json scripts (build/test/lint/publish) to pnpm; sets Lerna npmClient to pnpm; adds deploy dry-run/pack helpers
• Converts internal package dependencies to workspace:* and replaces analytics-types/client-common imports with @amplitude/analytics-core where applicable
• Code/test changes: export InstanceProxy and new proxy types in analytics-core; broaden tsconfig includes; add Jest transformIgnorePatterns for RN packages; update tests to use core types and mock browser client
• Session Replay: coerce string sessionId to number in targeting manager and add a unit test; tighten types in helpers
• Updates docs/templates (README, CONTRIBUTING, AGENTS, issue template) to pnpm instructions
• Publishing: refactors v2 and single-package workflows to pnpm commands; v1 keeps yarn; adjusts version/publish steps to pnpm

^{Written by Cursor Bugbot for commit 454f675. This will update automatically on new commits. Configure here.}

[macroscopeapp]

Migrate CI workflows, scripts, and workspaces to pnpm and update targeting-manager.evaluateTargetingAndStore in targeting-manager.ts to parse string sessionId values

Switch package management from Yarn to pnpm across CI, Husky hooks, workspace configs, and package scripts; add pnpm lock/workspace files; update inter-package dependencies to workspace:*; introduce core type exports and minor test config changes; and fix string-to-number sessionId handling in targeting.

📍Where to Start

Start with the workflow migration in .github/workflows/ci.yml and then review the sessionId parsing change in targeting-manager.ts.

Changes since #1458 opened

• Migrated prerelease publishing workflow from npm to pnpm package manager [73f6737]
• Removed test case verifying sessionId string-to-number parsing [c3e9774]
• Added test case verifying evaluateTargetingAndStore converts string sessionId to numeric format before calling evaluateTargeting [454f675]

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Macroscope summarized d8c094d.

[Copilot]

Pull request overview

This PR migrates the repository from Yarn v1 to PNPM to take advantage of performance and security improvements. The migration involves updating package manager references, workspace configurations, CI/CD workflows, and dependency declarations across the monorepo.

Key Changes:

• Migration from Yarn to PNPM as the package manager with workspace protocol for internal dependencies
• Updated all GitHub Actions workflows to use PNPM with proper caching setup
• Converted documentation and scripts to reference PNPM instead of Yarn

Reviewed changes

Copilot reviewed 75 out of 79 changed files in this pull request and generated 17 comments.

Show a summary per file

File	Description
pnpm-workspace.yaml	New PNPM workspace configuration with security settings
package.json	Updated packageManager field, scripts, and publish commands for PNPM
lerna.json	Changed npmClient from yarn to pnpm
packages/*/package.json	Converted dependencies to workspace:* protocol and updated scripts to use pnpm
.github/workflows/*.yml	Updated CI/CD workflows to use PNPM with setup-node v4 and caching
.husky/*	Updated git hooks to use pnpm commands
README.md, CONTRIBUTING.md, AGENTS.md	Updated documentation references from yarn to pnpm
test-server/README.md	Updated test server instructions to use pnpm
tsconfig.json	Removed 'idb' from types array
packages/*/test/tsconfig.json	Added test-specific TypeScript configs
packages/*/jest.config.js	Added transformIgnorePatterns for PNPM compatibility
packages/analytics-core/src/types/proxy.ts	New file exporting InstanceProxy type
packages/session-replay-browser/src/targeting/targeting-manager.ts	Bug fix for parsing string sessionId to number
packages/session-replay-browser/src/helpers.ts	Added explicit return type annotation
packages/plugin-experiment-browser/package.json	Fixed missing && operator in version script
Various test files	Updated imports and mocking strategies

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[Mercy811]

LGTM

[Mercy811]

LGTM!