refactor(async): add scoped resource lifecycle

[beruro]

Problem

The legacy async-data helper does not make scope changes, stale completions, unmount cancellation, or hidden-window polling ownership explicit, allowing old requests and duplicate timers to outlive their consumer.

Solution

• Introduce a scoped async-resource lifecycle with stale-result fencing and abort-on-scope-change/unmount behavior.
• Add visibility-aware polling that pauses while hidden and resumes without duplicate timers.
• Add shared latest-task and polling primitives with focused lifecycle tests.
• Include architecture, UI-consistency, and performance-guard audit records.
• Validation: 18 focused tests, TypeScript typecheck, changed-file ESLint, and diff check.

Potential risks

• This is the foundation for consumer migrations in refactor(data): scope async resource consumers #563 and bounded runtime work in perf(runtime): bound caches, scans, and background work #564.
• Incorrect scope keys could still retain stale data or cancel valid work; consumers must provide authoritative identity/resource scope.
• Visibility-paused resources must revalidate once on return without overlapping an existing request.