perf(extensions): clean sandbox lifecycle handles

[JustYannicc]

What changed

• Added a per-ExtensionView lifecycle scope that gives extension bundles scoped window and document objects during evaluation.
• Routed window.setInterval, window.setTimeout, window.requestAnimationFrame, window.addEventListener, and matching document listener APIs through the existing cleanup registry.
• Preserved bare timer cleanup and added cleanup metadata so handles are cleared through the host object that created them.
• Added a lifecycle harness that reproduces the pre-fix window.* leak and verifies cleanup on unmount and re-evaluation.

Why

Extension bundles could bypass the existing bare timer registry by calling window.* APIs from module scope or effects. No-view/background runs and remounted menu-bar extensions could then leave renderer DOM timers/listeners alive after the ExtensionView instance was gone.

Compatibility impact

• The scoped objects delegate ordinary reads and methods to the host window/document, including window.document, window.navigator, window.location, and window.electron.
• window, self, global, and globalThis resolve to the same scoped object inside the extension wrapper.
• Host renderer globals are not mutated; the scope is passed only as wrapper lexical arguments.
• Extensions that clean up their own timers/listeners still work: clear/remove calls untrack the registry before delegating.

Lifecycle evidence

node --test scripts/test-extension-lifecycle-sandbox.mjs:

• Pre-fix simulation: cleanup leaves intervals=1, windowListeners=1, documentListeners=1, total=3.
• Scoped cleanup: starts with the same total=3, registry sees intervals=1 and eventListeners=2, cleanup ends at total=0.
• Re-evaluation: 3 -> 0 -> 3 -> 0 across prior evaluation cleanup and final unmount.

How tested

• node --test scripts/test-extension-lifecycle-sandbox.mjs
• ./node_modules/.bin/vite build
• LSP diagnostics for src/renderer/src/ExtensionView.tsx: no errors
• ./node_modules/.bin/tsc -p tsconfig.renderer.json --noEmit was run and still fails on existing unrelated origin/main renderer type errors, including App.tsx, CameraExtension.tsx, raycast-api, settings, and quicklink icon typings.

Stack validation

• Clean PR branch from origin/main; no stacked integration commits included.
• Dependencies: none on perf(runtime): reduce extension and menubar churn #530, perf(ai): batch streaming and status updates #531, fix(validation): restore project checks #532, perf(renderer): cache icons and virtualize launcher surfaces #533, perf(mac): reduce native polling and async IO stalls #534, or perf(search): reduce indexing and ranking overhead #535.

[JustYannicc]

Superseded by consolidated runtime lifecycle/icon churn PR #558: #558