feat: upgrade CES templates to Expo SDK 57

[DavidJGrimsley]

Summary

• upgrade generated CES templates to Expo SDK 57 / React Native 0.86
• align Expo-managed package ranges with SDK 57, including Expo Router 57 and the updated Software Mansion stack
• remove obsolete generated New Architecture config and align CLI and website prebuild guidance with SDK 57's clean-by-default behavior
• correct the EAS completion output so it does not repeat an install step after dependencies were already installed

Files

• .changeset/expo-sdk-57-upgrade.md - records a paired minor release for create-expo-stack and rn-new with the SDK 57 upgrade notes
• bun.lockb - refreshes the workspace lockfile for the updated Expo dependency graph
• cli/package.json - aligns the CLI package's Expo dependency with SDK 57
• cli/src/templates/base/app.json.ejs - stops generating newArchEnabled; SDK 55+ always uses the New Architecture, so the setting is redundant
• cli/src/templates/base/package.json.ejs - updates generated app dependencies to the Expo SDK 57 / React Native 0.86 compatible versions
• cli/src/utilities/printOutput.ts - uses the new clean-by-default expo prebuild command and removes redundant install instructions from normal EAS output
• package.json - aligns the monorepo root Expo dependency with SDK 57
• www/demo/steps/printOutput.js - keeps the website CLI demo's prebuild instructions consistent with the real CLI

Verification

• bun run build:cli
• bun run snapshot-update
• bun run test
• generated a Bun + NativewindUI app and verified expo install --check, expo-doctor, and tsc --noEmit
• generated an npm + React Navigation + Unistyles app and verified expo install --check, expo-doctor, and tsc --noEmit
• directly verified the website demo output for npm, pnpm, Bun, and Yarn

[Copilot]

Pull request overview

This PR upgrades the generated Create Expo Stack (CES) templates (and the CLI’s own Expo dependency) to align with Expo SDK 57 / React Native 0.86, including updating Expo-managed package ranges, removing now-redundant New Architecture config, and adjusting prebuild guidance to match SDK 57 behavior.

Changes:

• Bump Expo dependency versions to SDK 57 across the repo and CLI.
• Update generated template dependencies to SDK 57-compatible Expo + Software Mansion versions (incl. Expo Router 57).
• Remove generated newArchEnabled config and update printed prebuild instructions for SDK 57’s default clean behavior.

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
package.json	Bumps repo-level Expo dependency to ~57.0.4.
cli/package.json	Bumps CLI’s Expo dependency to ^57.0.4.
cli/src/utilities/printOutput.ts	Updates printed prebuild guidance for SDK 57.
cli/src/templates/base/package.json.ejs	Updates generated template dependency versions to SDK 57 / RN 0.86 ranges.
cli/src/templates/base/app.json.ejs	Removes generated newArchEnabled config from template output.
.changeset/expo-sdk-57-upgrade.md	Adds a changeset documenting the SDK 57 upgrade and related template/CLI changes.

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[DavidJGrimsley]

@danstepanov It's ready. I generated some test apps and everything looks good.

PS I noticed the EAS install-condition fix in cli/src/utilities/printOutput.ts is unrelated to the SDK 57 upgrade. It fixes an older inverted condition that caused normal EAS output to repeat the package-install step.
Would you prefer I split that one-file bug fix into a separate PR and keep this PR focused on SDK 57? The prebuild guidance changes would remain here.

[danstepanov]

@DavidJGrimsley Expo SDK should probably live in next? I don't think that Expo has made SDK 57 the stable version yet. We'll also need to go through and update NativewindUI to SDK 57.