chore(react-native-plugin)!: require posthog-ios 4.0

[turnipdabeets]

Warning

Prep PR: CI is expected to fail until posthog-ios 4.0 is released. The iOS and macOS example builds can't resolve 4.0.0 from CocoaPods or SwiftPM yet. Merge into #5194 last, once 4.0 is published and CI is green. Plugin 3.0 is released only after this PR.

Problem

#5194 (plugin 3.0) keeps posthog-ios at 3.88.2. This is the follow-up that moves to posthog-ios 4.0, which needs Xcode 26 and raises the floors to iOS 15 and macOS 11 (the plugin already matches those in #5194).

Changes

• posthog_ios_version in the podspec and the floor in ios/Package.swift move to 4.0.0. check-spm-manifest.mjs keeps checking that they match.
• Changesets: Breaking posthog-ios 4.0 / Xcode 26, plus a patch entry for 4.0's behavior change: native uploads (replay, crash reports) pause while cellular data is turned off for the app, instead of sending requests that fail (PostHog/posthog-ios#909).
• ios/Package.swift depends on posthog-ios with traits: ["SessionReplay", "CrashReporting"], leaving out Surveys (PostHog/posthog-ios#916, #918). The plugin sets config.surveys = false and renders surveys in JS, so native surveys were dead weight. Replay and crash autocapture need the other two traits. Folded in from chore(react-native-plugin): leave out posthog-ios's Surveys trait #5238.
• ios/Package.swift moves from tools 6.0 to 6.2. Traits need 6.1+, and posthog-ios 4.0 already requires Xcode 26 (Swift 6.2).
• Only the full-SwiftPM path drops Surveys. CocoaPods has no traits and posthog.useSpm passes none, so both still get the full SDK. SwiftPM turns a trait back on if any other package depends on posthog-ios with the defaults; nothing breaks, the code just isn't dropped.
• The plugin's Swift needs no changes for 4.0. Built locally against a merge of the 4.0 stack: examples/example-rn-native-plugin simulator Debug build succeeded with no plugin warnings once chore(react-native-plugin): drop screenshotMode for posthog-ios 4.0 #5236 is applied.

Before merging

• ci(react-native-plugin): build CocoaPods lanes on Xcode 26 #5226 (CocoaPods CI lanes on Xcode 26) is merged; 4.0 can't build on the old Xcode 16.2 lanes.
• posthog-ios 4.0 is published to CocoaPods trunk and tagged for SwiftPM. CocoaPods trunk goes read-only on 2 Dec 2026, so if 4.0 ships after that, the default CocoaPods path can't resolve it.
• chore(react-native-plugin): drop screenshotMode for posthog-ios 4.0 #5236 (drop the deprecated screenshotMode) can merge into chore(react-native-plugin)!: Major Release v3 #5194 before this PR. It's only correct with posthog-ios 4.0, so 3.0 can't release without this PR.
• posthog-ios 4.0 ships the SessionReplay, CrashReporting and Surveys traits (feat(web-analytics): Add site_name in config and $site_name property #916/feat: Show warning if identifying with "distinct_id" #918 are merged into the 4.0 stack). Naming a trait that doesn't exist fails package resolution.
• PostHog/posthog-ios#909 is in 4.0. It's still open; if it's dropped, delete .changeset/rn-plugin-posthog-ios-4-cellular.md.
• posthog.com React Native docs list Xcode 26 as a requirement (the plugin README only links to the docs).

Release info Sub-libraries affected

Libraries affected

• All of them
• posthog-js (web)
• posthog-js-lite (web lite)
• posthog-node
• posthog-react-native
• @posthog/react-native-plugin
• @posthog/react
• @posthog/ai
• @posthog/convex
• @posthog/next
• @posthog/nextjs-config
• @posthog/nuxt
• @posthog/openfeature-node-provider
• @posthog/openfeature-web-provider
• @posthog/rollup-plugin
• @posthog/webpack-plugin
• @posthog/types
• @posthog/browser-common

Checklist

• Tests for new code (no new behavior; plugin tests and manifest check pass)
• Accounted for the impact of any changes across different platforms
• Accounted for backwards compatibility of any changes (no breaking changes!) (intentional: posthog-ios 4.0 needs Xcode 26; rides the plugin's 3.0 major)
• Took care not to unnecessarily increase the bundle size

If releasing new changes

• Ran pnpm changeset to generate a changeset file

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Made with Claude Code. Split out of #5226 so that PR (Xcode 26 CI lanes) can merge now, then split again for the traits change (#5238), which is now folded back in. The 4.0 build check merged #873 with the open 4.0 PRs locally, since 4.0 isn't tagged; #907 and #916 conflict on two color-util files there, so the iOS stack needs a rebase. Not tested: the posthog.useSpm path against 4.0, Release builds, running the app.

🤖 Generated with Claude Code