- Add check-trailing-whitespace Makefile target to detect trailing
  whitespaces in source files
- Add fix-trailing-whitespace Makefile target to automatically remove
  trailing whitespaces
- Create CI workflow to check for trailing whitespaces on all pushes
- Update CLAUDE.md with trailing whitespace removal requirements
- Wrap Makefile target commands to 80 characters for better readability

All file types covered: .rs, .toml, .md, .yaml, .yml, .json, .ts, .tsx,
.js, .jsx with appropriate directory exclusions for build artifacts and
dependencies.

- Create docs.yaml workflow for documentation CI/CD with:
  * Documentation build testing and broken link detection
  * Rust API documentation generation and integration
  * GitHub Pages deployment on develop branch
  * Versioned documentation creation on tag releases

- Update Docusaurus config to include API documentation links
- Add Makefile targets for Rust documentation integration

Applied automatic trailing whitespace removal across the codebase using
the new fix-trailing-whitespace Makefile target. This ensures consistent
formatting and prevents future trailing whitespace commits.

Files affected:
- Rust source files (.rs)
- Configuration files (.toml, .yml, .yaml)
- Documentation files (.md)
- Frontend files (.js, .ts, .tsx)
- Various other project files

This is a formatting-only change with no functional modifications.

Convert all bare URLs to proper hyperlinks by wrapping them with angle
brackets. This resolves the "this URL is not a hyperlink" warnings when
running make docs-rust.

Changes:
- Wrapped all bare URLs in documentation comments with <> brackets
- Fixed URLs in module-level docs (//\!), regular docs (///), and comments (//)
- Processed all .rs files in the workspace excluding build artifacts

All documentation URLs are now properly formatted as clickable hyperlinks
in the generated API documentation.

- Add sqlite3 to build dependencies
- Initialize SQLite database with heartbeats-processor schema
- Set DATABASE_URL to file-based SQLite database for SQLx validation
- Enables compile-time query checking for heartbeats-processor

Fixes "set DATABASE_URL to use query macros online" errors in CI