Add v1.3 history and reliability workflow

[StoneHub]

What changed

• adds an extension-owned History & Export page for normal pages, PDFs, and protected surfaces
• serializes per-site history mutations to prevent same-origin tab overwrites
• moves transient full-viewport screenshots into session storage with expiry and editor-close cleanup
• hides injected extension UI before Region screenshots
• adds mouse, touch, pen, and keyboard Region selection support
• adds JSON and self-contained HTML report downloads with embedded crop images
• adds lightweight PR/main CI, exact ZIP verification, and SHA-256 release assets
• updates source documentation for unreleased v1.3 while keeping published metadata on v1.2.0

Why

Region capture was easier to create than retrieve or hand off. Transient screenshots could also outlive abandoned editor tabs, and whole-array site history writes could lose updates when multiple same-origin tabs were open.

Validation

• npm test
• npm run check
• npm run package
• npm run verify:package
• git diff --check
• verified 15-file dev-feedback-capture-v1.3.0.zip

Manual gate remaining

Before merge or release, load the unpacked extension in Edge/Chrome and smoke-test Element mode, Region/PDF mode, same-site multi-tab history, overlay-free screenshots, keyboard selection, and JSON/HTML exports.