Enhanced version detection, provider lifecycle, and release automation

Features:
- Version detection with BuildInfo fallback for go install users
- Provider initialization refactoring with improved lifecycle management
- Release automation slash command for streamlined releases

Bug Fixes:
- MCP server startup failure (hardcoded binary path)
- MCP configuration documentation (correct .mcp.json location)

Other Changes:
- Update README to show current version instead of @latest
- Add .mcp.json.example as configuration reference
- Improve Taskfile.yml LDFLAGS module path

Full Changelog: https://github.com/mvp-joe/project-cortex/compare/v1.2.0...v1.3.0