Adds a thin LSP bridge daemon (tools/_lib/lsp/) that manages LSP server
processes on demand, with adapters for gopls, clangd, and intelephense.
Tool scripts:
- lsp_definition: go to definition
- lsp_references: find all references
- lsp_hover: type/doc info
- lsp_rename: rename symbol (applies edits directly)
- lsp_symbols: document/workspace symbols
- lsp_diagnostics: errors and warnings