[cppbear]

Problem

The public entry points need clearer examples and an easier route to the offline quick start. Static presentation changes also trigger unnecessary Rust validation.

Change

• Illustrate analysis, test generation, and compilation repair; refine desktop/mobile presentation and add social previews.
• Reorganize the README around the quick start, add responsive diagrams, and replace the poster with the revised version.
• Skip Rust checks for explicitly listed static/documentation/metadata changes; retain Pages asset checks and add JavaScript syntax validation.

Validation

• Local desktop/mobile and keyboard, reduced-motion, clipboard, and no-JavaScript checks passed.
• Static references, sharing metadata, patch checks, and 54 CI-scope/Pages checks passed.
• The full Rust suite was not rerun locally. This PR changes the native CI workflow, so CI still performs full validation.