NYou can write your own tRPC middleware and put the user in Context
NYou are able to add middleware(s) to a procedure with the t.procedure.use() method. The middleware(s) will wrap the invocation of the procedure and must pass through its return value.
NI think you're figuring it out yes 
Nheaders can be an async function I believe, so you can await that
NI would call getAuthToken inline there too, not in the component.