Fix interactive element selection granularity - #52

Summary

• select the nearest instrumented or semantic interactive DOM boundary instead of promoting dependency-owned controls to a larger traced wrapper
• keep unavailable dependency source evidence explicit and disable editor navigation when coordinates are unavailable
• support whitespace-token ARIA fallback roles and add a deliberately uninstrumented React fixture
• prepare 1.0.0-beta.7 release metadata

Verification

• pnpm check
• pnpm test:e2e:firefox
• React 19 Chromium E2E: 11/11
• Firefox E2E: 3/3
• real-browser verification of an uninstrumented router link, traced controls, ordinary text, and repeated menu clicks
• staged diff privacy scan: no workspace names, private app paths, localhost target, or npm credentials

Closes #51