v4.0.0 stable release checklist #754

Tracking issue for the v4 stable release, so the remaining steps happen in the right order. Context: v4 now lives on master (canaries under next-v4), v3 moved to the 3.x maintenance branch (canaries under next-v3, git-cliff flow). The dist-tag matrix and the flow are documented in RELEASE.md.

Before the release

• Resolve the crawlee 4.0.0-beta.201 incompatibility: EventManager gained a native #private brand and PlatformEventManager extends EventManager no longer type-checks across the package boundary; the graph is pinned at 4.0.0-beta.200 until then
• Wait for crawlee 4.0.0 stable, then move the crawlee pins (currently 4.0.0-rc.1) to ^4.0.0
• Wait for apify-client 3.0.0 stable, then normalize apify-client from ^3.0.0-rc.0 (chore(deps): update apify-client to 3.0.0-rc.0 #772) to ^3.0.0
• Finalize the upgrading guide (docs/04_upgrading/upgrading_v4.md) - it must compare released 3.x to 4.0, including the apify-client v3 adaptation (docs: cover the apify-client v3 changes in the v4 upgrading guide #773) and Actor.getInput() throwing ActorInputError
• Publish an RC (publish-to-npm.yaml with tag: rc) - 4.0.0-rc.0
• Validate the RC on the platform
• Triage the open master PRs (feat: add explicit platform detection helper #670, feat: add key-value record public URL #669, docs: add status message section to Actor lifecycle page #586) - they predate the cutover and need rebasing (chore(deps): remove fast-uri override #641 is merged)

Release day, in order

• Dispatch release.yaml on master with release_type: auto (confirm git-cliff derives 4.0.0; use custom + 4.0.0 otherwise). This publishes to latest, commits the changelog, creates the GitHub release, and snapshots the 4.0 docs via the version_docs job.
• On master: switch the canary dist-tag in test-and-release.yaml from next-v4 to next, and drop the premajor_version wiring for the next tag in publish-to-npm.yaml
• On 3.x: switch release.yaml's publish step from tag: latest to latest-v3, and add latest-v3 to publish-to-npm.yaml's tag choices. Do this the same day, otherwise the next v3 patch release knocks v4 off latest.
• Registry dist-tag cleanup: delete the orphan v4 and beta tags, point or delete next-v4, then check pnpm view apify dist-tags shows latest/next/next-v3 where expected
• Announce (release notes)
• Close this issue