build: parallelize engine builds with turbo

[kpal81xd]

Supersedes #8357.

Important

Watch mode is intentionally out of scope for this PR. It remains on the existing single Rollup watcher (node build.mjs --watch) and will be addressed in a follow-up build-system/watch PR.

Summary

Parallelizes the engine build pipeline with Turbo for completed build tasks. Also simplifies Rollup target generation so minified builds no longer depend on generated release artifacts.

Changes

• Move aggregate build orchestration into turbo.json
• Add explicit --type and --format build options
• Rename build types to concise task names: rel, dbg, prf, min
• Simplify Rollup target generation by removing the in-memory HISTORY dependency flow
• Emit bundled and preserved-module ESM outputs from one Rollup target
• Minify through a Rollup output plugin so min tasks build directly from source
• Keep clean as an explicit utility script without making Turbo build tasks depend on it
• Keep tree visualizer scripts generating both ESM and UMD graphs by default
• Clean Rollup output when running through Turbo so logs keep the Turbo task prefix
• Keep generated output filenames unchanged

Build timings

Clean sequential timings with build/ and .turbo/ removed before each run.

Build	Old	New	Improvement
full build	32.53s	12.77s	60.7%
release / rel aggregate	7.71s	5.73s	25.7%
debug / dbg aggregate	8.43s	5.78s	31.4%
profiler / prf aggregate	7.96s	5.39s	32.3%
umd aggregate	11.31s	6.34s	43.9%
esm aggregate	14.42s	7.96s	44.8%

Public API changes

No engine runtime API changes.

Developer-facing npm script migrations:

Old script	New script
build:release	build:rel:umd, build:rel:esm
build:debug	build:dbg:umd, build:dbg:esm
build:profiler	build:prf:umd, build:prf:esm
build:umd	build:rel:umd, build:dbg:umd, build:prf:umd, build:min:umd
build:esm	build:rel:esm, build:dbg:esm, build:prf:esm, build:min:esm
build:esm:release	build:rel:esm
build:esm:debug	build:dbg:esm

New npm script: clean.

build.mjs now accepts --type <rel|dbg|prf|min|types> and --format <esm|umd>, with rel and esm as the defaults for regular builds. Tree visualizer flags default to both formats when --format is omitted.

Manual tests

• npm run build:treemap (verified treemap.es.html and treemap.umd.html)
• Parsed turbo.json and asserted no build task depends on clean
• node --check build.mjs
• npm run lint

[Copilot]

Pull request overview

This PR parallelizes the PlayCanvas engine build pipeline by moving build orchestration into Turbo, allowing independent Rollup targets (UMD/ESM/types and rel/dbg/prf/min variants) to run concurrently instead of being coordinated by a single serial build process.

Changes:

• Introduces turbo.json to define build task graph (aggregate tasks + leaf targets) and adds Turbo as a dev dependency.
• Refactors build.mjs to a typed CLI (--type, --format, --watch, --sourcemaps, tree visualizer flags) and updates Rollup environment wiring accordingly.
• Renames build types (release/debug/profiler → rel/dbg/prf) across build utilities and example build config, and updates npm scripts/watch aliases.

Reviewed changes

Copilot reviewed 6 out of 8 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
utils/rollup-build-target.mjs	Renames build types and adds a bundleSource option to support minifying from a previously-generated rel bundle.
turbo.json	Adds Turbo task graph describing build aggregates and leaf build outputs for caching/parallelism.
rollup.config.mjs	Switches Rollup target selection to process.env.build / process.env.bundleSource and updates build-type naming.
package.json	Adds Turbo + packageManager, rewires build/watch scripts to Turbo and new build.mjs flags, updates build-type naming.
package-lock.json	Locks Turbo and its optional platform binaries.
examples/rollup.config.mjs	Updates example engine build targets to use rel/dbg/prf build type names.
build.mjs	Replaces legacy env-arg forwarding with a typed CLI + spawn-based Rollup runner and output “cleaning”.
.gitignore	Ignores the .turbo directory.

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 8 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 6 out of 8 changed files in this pull request and generated 2 comments.