FU: Initial transition from TUWF

Seems to be working alright, and it does clean up a few things. The
biggest missing thing right now is schema-based validation for some
query parameters. I'm also seeing opportunities for FU::Pg to act as a
hash/shorthash codec, simplifying some error-prone manual conversions.

README.md

@@ -7,18 +7,14 @@ Ironically, documentation about how things work is completely lacking.
 
 ## Requirements
 
-- perl: A somewhat recent version (no idea which, due to my XS usage)
-- postgresql: Also a somewhat recent version
+- perl: 5.36+
+- postgresql: A somewhat recent version
 - rust: Version who-knows-which
 
 ### Web front-end
 
+- FU
 - AnyEvent
-- DBD::Pg
-- DBI
-- JSON::XS
-- SQL::Interp
-- TUWF
 
 ### Man page indexer