Updates workflow tool names, documentation references, and internal naming
conventions across MCP server, CLI, tests, and web components to complete
the singularity-forge rebrand from gsd to sf.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Final rebrand: rename remaining Rust source file to complete the gsd → forge
transition. All parser references already use forge_parser after earlier commits.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>