kindsys: Adapt to new flattened lineage syntax in Thema (#68034)

* Update all core kinds to flattened lineages

* Regen Go types, without any

* Regen Go types, s/interface{}/any/

* Update generated core typescript

* Update generate docs

* Fix defaults gen in veneer index jenny

* Flatten plugindef lineage

* Convert all plugin kinds to flattened form

* Switch back to interface{} for now

* Switch to fs.Sub in plugin DeclParser

* Mostly undesirable codegen changes, to be fixed

* Update mod and sum

* Update pfs tests to flattened lineages

* Update thema to latest, regen docs

pkg/plugins/pfs/decl_parser.go

@@ -3,7 +3,6 @@ package pfs
 import (
 	"fmt"
 	"io/fs"
-	"os"
 	"path/filepath"
 	"sort"
 
@@ -39,7 +38,7 @@ func (psr *declParser) Parse(root fs.FS) ([]*PluginDecl, error) {
 			continue
 		}
 
-		dir := os.DirFS(path)
+		dir, _ := fs.Sub(root, path)
 		pp, err := ParsePluginFS(dir, psr.rt)
 		if err != nil {
 			return nil, fmt.Errorf("parsing plugin failed for %s: %s", dir, err)