I need to find in files string "WebUser" within the project root "/app" (means only in project files).

However, I want to exclude "/app/vendor/" directory from search.
This is default directory used e.g. by composer - it's really huge - and contains third party libraries, framework classes, etc etc
"/app/vendor/" is necessary for class/traits/obejcts declarations (code inspection), but bad for searching (often contains large files, may have 50 - 100 MB ...).

When I hide directory "/app/vendor" via Projects properties, then it will be excluded from file search (which is my goal), but it will not find class declarations (undesired side effect).
E.g. CTRL + classname returns Failed to find "xxxxxx" class (or trait).

My question is:
How to exclude directories ONLY from search, while keeping it availble for IDE object parsing capabilities (code inspection)?

Thank you.