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/sfxrlua/rockspec/sfxr-0.0.2-1.rockspec

@@ -0,0 +1,28 @@
+package = "sfxr"
+version = "0.0.2-1"
+source = {
+  url = "git://github.com/nucular/sfxrlua",
+  tag = "v0.0.2"
+}
+description = {
+  summary = "A port of the sfxr sound effect synthesizer to Lua",
+  detailed = [[
+    A port of the sfxr sound effect synthesizer to pure Lua, designed to be used
+    together with the awesome LÖVE game framework.
+  ]],
+  homepage = "https://github.com/nucular/sfxrlua",
+  license = "MIT/X11"
+}
+dependencies = {
+  "lua ~> 5.1"
+  -- bitop?
+}
+build = {
+  type = "builtin",
+  modules = {
+    sfxr = "sfxr.lua"
+  },
+  copy_directories = {
+    "docs"
+  }
+}