Constant TREE_SITTER_SYMBOL_SOURCE_ID 

pub const TREE_SITTER_SYMBOL_SOURCE_ID: &str = "gen:tree-sitter-symbol";

Source id for the host-orchestrated tree-sitter local-symbol source (Phase 4.2.g.6 (1/2)). Walks the buffer’s syntax tree per popup-trigger via lattice_syntax::Syntax::collect_symbols.