feat: styles improvement and repo info

[prettyleaf]

This pull request enhances the build metadata pipeline and significantly improves the status page's header by surfacing detailed build information, such as commit, branch, build time, and CI run number. It also refactors the build process to consistently inject this metadata, updates the UI to display it in a modern, interactive popover, and documents these changes. The result is a more informative and user-friendly status page that helps users and maintainers quickly identify the running build and its provenance.

Build metadata injection and propagation:

• The build process now captures additional metadata (COMMIT, BRANCH, BUILD_TIME, BUILD_NUMBER) in both GitHub Actions workflows (build-dev.yml, docker.yml) and passes them as build arguments to Docker and via -ldflags for Go binaries. [1] [2] [3] [4] [5] [6]
• The Makefile is updated to provide these arguments for local builds as well, ensuring parity between CI and local environments. [1] [2]

Backend code changes for build metadata:

• The main application (main.go) defines variables for all build metadata and exposes them via a new buildInfo() function, which is then passed to the server and admin handlers. [1] [2] [3] [4] [5] [6] [7] [8]

Status page UI and UX improvements:

• The status page header is redesigned: the version chip now opens a popover with full build details (commit, branch, build time, CI run number), a link to the latest release, and a refresh button. The layout and styles are updated for clarity and responsiveness, including improved handling of outdated builds. [1] [2] [3]
• The columns layout is improved to ensure a consistent two-column display regardless of screen size.

Documentation updates:

• The README.md and README.ru.md files are updated to describe the new build popover and clarify how and where build metadata is displayed. [1] [2]

These changes provide clear, actionable build provenance directly in the status page UI and ensure that all builds (local and CI) are consistently annotated with their metadata.