◇ Could this help me?
Yes for the workspace idea, no for the packaged install. Running an assistant next to a visible file tree genuinely changes the work, because the context stops being something described in a chat message and becomes something both sides can see, and that benefit applies to writing and research just as much as to code. The part to refuse is the delivery mechanism: a one-click bundle of a stranger's extensions and settings installs code with access to everything open in the editor, and the fact that it is convenient is not a safety argument. What to do instead is add the two or three extensions that actually matter, from their official listings, one at a time. General practice, with the reminder that the editor being better than the desktop application is the creator's preference rather than a finding.
I want to set up a code editor as a general workspace rather than for coding, with an assistant working alongside my files. Walk me through what I would need: which official extensions provide the assistant panel, what gives me a readable document preview, and what the minimum configuration is to see my file tree, my document, and the assistant at the same time. For every extension, name the publisher and the official marketplace listing, tell me what access it has to my files and what it sends anywhere, and wait for my approval before anything gets installed. Do not use anyone's prepackaged settings bundle. Then tell me what I would lose compared with the dedicated desktop application.