nimbus pairing 2023-11-21 megaticket

[aryairani]

• [ ] paths with punctuation don't round-trip #2970
• [ ] #4422
• [x] #4423
• [x] long lags at unexpected times — maybe "loading root branch" related
• [ ] set root to a time before a branch existed causes desync between namespace and branch tables
• [ ] undo takes forever (to produce output?)
• [x] pretty printer using ctor suffix but can't parse it in scratch file / e.g. ServerState.currentRegion, http.handleIncomingRequest
• [x] aliased stuff gets doubled in scratch file, some definitions not distinguished by suffixifier but then ambiguous in parsing.
• [ ] we should be testing round trip and other features on nimbus / base / remote etc.

[stew]

I deleted some terms, then restarted ucm, then ran "ls" (to get it "warmed up"? the first command always takes the longest), then ran "undo" and it immediately used all 44 gigs of available memory. I peaked at about 6 gigs of swap usage. It took 7 minutes to complete