Browser extensions

Use the native ExtensionConfig and scaffold/build/package APIs for MV3 targets.
Read the current target and store adapters before planning distribution; a
successful local bundle is not proof of store acceptance or device behavior.

Build workflow

scaffoldExtensionProject creates the established project layout;
scaffoldSafariApp owns Safari container scaffolding. buildExtension configures
popup/options pages, background/content scripts,
static assets and declarativeNetRequest rules. Native page builds use stx,
resource partials and CSP sanitization rather than embedding arbitrary inline
script. Keep code in permitted bundled entrypoints and minimize permissions.

Target-specific manifest generation, packaging and validation support Chrome
and Firefox. Safari additionally uses container-app scaffolding, resource sync
and xcodebuild on a suitable macOS toolchain. Target limitations are explicit;
do not substitute one browser's package for another.

Store preparation and publication

The package includes publish plans and adapters for Chrome Web Store, Firefox
Add-ons/previews and App Store Connect submission. Prepare a reviewable plan,
credentials prerequisites and the actual artifacts before an authorized upload.
Do not upload or submit merely because the build finished. Never put store
credentials into the extension's public files.

Verify generated manifests, CSP, permissions, scripts, packaged file lists,
and target-specific tests. Device and store outcomes need their own evidence.
Source: core/browser-extension/src/{config,manifest,build,package,scaffold,
publish-plan,safari}.ts and store adapters. Tests cover these same boundaries.