configuration_import_roots

`importRoots` is an optional array of alias-to-directory mappings in `.reqlan/config.json`.
Each mapping has:
- `alias` ( required non-empty string ): prefix before `/` in aliased import paths.
- `root` ( optional non-empty string ): directory for that alias.
A relative `root` resolves against the base root ( the parent of `.reqlan` ), not against the `.reqlan` directory.
An absolute path or `file://` URI is used as that alias' import-root directory directly.
When `root` is omitted for a mapping, that alias uses the workspace folder that contains the `.rq` file.
When `importRoots` is omitted, empty, or has no valid entries, the default is one mapping with alias `@` and no explicit root.
When several aliases could match a path, the longest alias wins.
Invalid or unreadable JSON, and a non-array `importRoots` value, fall back to defaults ( or no loaded config for discovery, then defaults at resolve time ).
Language path forms and `@/` shorthand: import_paths and configuration_import_root_alias.
Schema: configuration_schema_file. Applying file discovery: configuration_location.
Editor completion of aliased import paths: code_completion.

Interactive page: configuration_import_roots