Load every dep module declared by items’s Module.depends, plus
every transitive dep, into codegen::ModuleInfo records ready to
hand to PipelineConfig.dep_modules.
Load a dependency tree starting from root_deps.
Returns modules in dependency order (leaves first).
Validates module declarations and detects circular imports.
Sibling of load_module_tree that resolves dependency modules
from an in-memory file map instead of the filesystem. Used by the
playground so a browser-side virtual fs can compile a multi-file
project without disk IO.
Convert pre-loaded modules (parsed virtual-fs items from the
playground / LSP / audit paths) into ModuleInfo records suitable
for PipelineConfig.dep_modules and SymbolTable::build.