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/signal.lua

@@ -0,0 +1,102 @@
+--[[
+Copyright (c) 2012-2013 Matthias Richter
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+Except as contained in this notice, the name(s) of the above copyright holders
+shall not be used in advertising or otherwise to promote the sale, use or
+other dealings in this Software without prior written authorization.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+]]--
+
+local Registry = {}
+Registry.__index = function(self, key)
+	return Registry[key] or (function()
+		local t = {}
+		rawset(self, key, t)
+		return t
+	end)()
+end
+
+function Registry:register(s, f)
+	self[s][f] = f
+	return f
+end
+
+function Registry:emit(s, ...)
+	for f in pairs(self[s]) do
+		f(...)
+	end
+end
+
+function Registry:remove(s, ...)
+	local f = {...}
+	for i = 1,select('#', ...) do
+		self[s][f[i]] = nil
+	end
+end
+
+function Registry:clear(...)
+	local s = {...}
+	for i = 1,select('#', ...) do
+		self[s[i]] = {}
+	end
+end
+
+function Registry:emitPattern(p, ...)
+	for s in pairs(self) do
+		if s:match(p) then self:emit(s, ...) end
+	end
+end
+
+function Registry:registerPattern(p, f)
+	for s in pairs(self) do
+		if s:match(p) then self:register(s, f) end
+	end
+	return f
+end
+
+function Registry:removePattern(p, ...)
+	for s in pairs(self) do
+		if s:match(p) then self:remove(s, ...) end
+	end
+end
+
+function Registry:clearPattern(p)
+	for s in pairs(self) do
+		if s:match(p) then self[s] = {} end
+	end
+end
+
+-- instancing
+function Registry.new()
+	return setmetatable({}, Registry)
+end
+
+-- default instance
+local default = Registry.new()
+
+-- module forwards calls to default instance
+local module = {}
+for k in pairs(Registry) do
+	if k ~= "__index" then
+		module[k] = function(...) return default[k](default, ...) end
+	end
+end
+
+return setmetatable(module, {__call = Registry.new})