cmd/pkgserver: flatten static site

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/pkgserver/internal/ui/ui_full.go

@@ -2,9 +2,20 @@
 
 package ui
 
-import "embed"
+import (
+	"embed"
+	"io/fs"
+)
 
 //go:generate tsc
 //go:generate cp index.html style.css static
 //go:embed static
-var content embed.FS
+var _static embed.FS
+
+var static = func() fs.FS {
+	if f, err := fs.Sub(_static, "static"); err != nil {
+		panic(err)
+	} else {
+		return f
+	}
+}()