Vendor libs/hump, sfxrlua, json4lua, narrator as real files

These were committed as empty submodule gitlinks with no .gitmodules,
so the folders were never populated and the game could not load
(require of libs/hump/timer, libs/sfxrlua/sfxr, narrator.narrator).
Checked out each at its pinned commit and vendored the files, matching
the existing bundled-libs convention. Removed the junk libs/libs/ tree.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

libs/json4lua/examples/timetrials.lua

@@ -0,0 +1,46 @@
+--[[
+  Some Time Trails for the JSON4Lua package
+]]--
+
+
+require('json')
+require('os')
+require('table')
+
+local t1 = os.clock()
+local jstr
+local v
+for i=1,100 do
+  local t = {}
+  for j=1,500 do
+    table.insert(t,j)
+  end
+  for j=1,500 do
+    table.insert(t,"VALUE")
+  end
+  jstr = json.encode(t)
+  v = json.decode(jstr)
+  --print(json.encode(t))
+end
+
+for i = 1,100 do
+  local t = {}
+  for j=1,500 do
+    local m= math.mod(j,3)
+    if (m==0) then
+      t['a'..j] = true
+    elseif m==1 then 
+      t['a'..j] = json.null
+    else
+      t['a'..j] = j
+    end
+  end
+  jstr = json.encode(t)
+  v = json.decode(jstr)
+end
+
+print (jstr)
+--print(type(t1))
+local t2 = os.clock()
+
+print ("Elapsed time=" .. os.difftime(t2,t1) .. "s")