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/hump/hump-0.4-2.rockspec

@@ -0,0 +1,33 @@
+package = "hump"
+version = "0.4-2"
+source = {
+   url = "git://github.com/vrld/hump"
+}
+description = {
+   summary = "Lightweight game development utilities",
+   detailed = [[Collection of independent components that implement common task needed in games:
+  - Gamestates that can stack on each other (e.g., for menus)
+  - Timers and Tweens with thread-like scripting support
+  - Cameras with camera movement control (locking, smooth follow, etc)
+  - 2D vector math
+  - Signals and Slots
+  - Prototype-based OOP helper
+  ]],
+   homepage = "https://hump.readthedocs.io",
+   license = "MIT",
+}
+dependencies = {
+  "lua >= 5.1"
+}
+build = {
+   type = "builtin",
+   modules = {
+      ["hump.camera"] = "camera.lua",
+      ["hump.class"] = "class.lua",
+      ["hump.gamestate"] = "gamestate.lua",
+      ["hump.signal"] = "signal.lua",
+      ["hump.timer"] = "timer.lua",
+      ["hump.vector"] = "vector.lua",
+      ["hump.vector-light"] = "vector-light.lua"
+   },
+}