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/json4lua-1.0.0-1.rockspec

@@ -0,0 +1,32 @@
+package="JSON4Lua"
+version="1.0.0"
+source = {
+  url = "git://github.com/craigmj/json4lua.git",
+  tag = "1.0.0"
+}
+description = {
+   summary = "JSON4Lua and JSONRPC4Lua implement JSON (JavaScript Object Notation) encoding and decoding and a JSON-RPC-over-http client for Lua.",
+   detailed = [[
+      JSON4Lua and JSONRPC4Lua implement JSON (JavaScript Object Notation)
+      encoding and decoding and a JSON-RPC-over-http client for Lua.
+      JSON is JavaScript Object Notation, a simple encoding of
+      Javascript-like objects that is ideal for lightweight transmission
+      of relatively weakly-typed data. A sub-package of JSON4Lua is
+      JSONRPC4Lua, which provides a simple JSON-RPC-over-http client and server
+      (in a CGILua environment) for Lua.
+   ]],
+   homepage = "http://github.com/craigmj/json4lua/",
+   license = "GPL"
+}
+dependencies = {
+   "lua >= 5.2",
+   "luasocket",
+}
+
+build = {
+   type = "builtin",
+   modules = {
+     ["json"] = "json/json.lua",
+     ["json.rpc"] = "json/rpc.lua"
+   }
+}