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/vector-light.lua

@@ -0,0 +1,186 @@
+--[[
+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 sqrt, cos, sin, atan2 = math.sqrt, math.cos, math.sin, math.atan2
+
+local function str(x,y)
+	return "("..tonumber(x)..","..tonumber(y)..")"
+end
+
+local function mul(s, x,y)
+	return s*x, s*y
+end
+
+local function div(s, x,y)
+	return x/s, y/s
+end
+
+local function add(x1,y1, x2,y2)
+	return x1+x2, y1+y2
+end
+
+local function sub(x1,y1, x2,y2)
+	return x1-x2, y1-y2
+end
+
+local function permul(x1,y1, x2,y2)
+	return x1*x2, y1*y2
+end
+
+local function dot(x1,y1, x2,y2)
+	return x1*x2 + y1*y2
+end
+
+local function det(x1,y1, x2,y2)
+	return x1*y2 - y1*x2
+end
+
+local function eq(x1,y1, x2,y2)
+	return x1 == x2 and y1 == y2
+end
+
+local function lt(x1,y1, x2,y2)
+	return x1 < x2 or (x1 == x2 and y1 < y2)
+end
+
+local function le(x1,y1, x2,y2)
+	return x1 <= x2 and y1 <= y2
+end
+
+local function len2(x,y)
+	return x*x + y*y
+end
+
+local function len(x,y)
+	return sqrt(x*x + y*y)
+end
+
+local function fromPolar(angle, radius)
+	radius = radius or 1
+	return cos(angle)*radius, sin(angle)*radius
+end
+
+local function randomDirection(len_min, len_max)
+	len_min = len_min or 1
+	len_max = len_max or len_min
+
+	assert(len_max > 0, "len_max must be greater than zero")
+	assert(len_max >= len_min, "len_max must be greater than or equal to len_min")
+
+	return fromPolar(math.random()*2*math.pi,
+	                 math.random() * (len_max-len_min) + len_min)
+end
+
+local function toPolar(x, y)
+	return atan2(y,x), len(x,y)
+end
+
+local function dist2(x1,y1, x2,y2)
+	return len2(x1-x2, y1-y2)
+end
+
+local function dist(x1,y1, x2,y2)
+	return len(x1-x2, y1-y2)
+end
+
+local function normalize(x,y)
+	local l = len(x,y)
+	if l > 0 then
+		return x/l, y/l
+	end
+	return x,y
+end
+
+local function rotate(phi, x,y)
+	local c, s = cos(phi), sin(phi)
+	return c*x - s*y, s*x + c*y
+end
+
+local function perpendicular(x,y)
+	return -y, x
+end
+
+local function project(x,y, u,v)
+	local s = (x*u + y*v) / (u*u + v*v)
+	return s*u, s*v
+end
+
+local function mirror(x,y, u,v)
+	local s = 2 * (x*u + y*v) / (u*u + v*v)
+	return s*u - x, s*v - y
+end
+
+-- ref.: http://blog.signalsondisplay.com/?p=336
+local function trim(maxLen, x, y)
+	local s = maxLen * maxLen / len2(x, y)
+	s = s > 1 and 1 or math.sqrt(s)
+	return x * s, y * s
+end
+
+local function angleTo(x,y, u,v)
+	if u and v then
+		return atan2(y, x) - atan2(v, u)
+	end
+	return atan2(y, x)
+end
+
+-- the module
+return {
+	str = str,
+
+	fromPolar       = fromPolar,
+	toPolar         = toPolar,
+	randomDirection = randomDirection,
+
+	-- arithmetic
+	mul    = mul,
+	div    = div,
+	idiv   = idiv,
+	add    = add,
+	sub    = sub,
+	permul = permul,
+	dot    = dot,
+	det    = det,
+	cross  = det,
+
+	-- relation
+	eq = eq,
+	lt = lt,
+	le = le,
+
+	-- misc operations
+	len2          = len2,
+	len           = len,
+	dist2         = dist2,
+	dist          = dist,
+	normalize     = normalize,
+	rotate        = rotate,
+	perpendicular = perpendicular,
+	project       = project,
+	mirror        = mirror,
+	trim          = trim,
+	angleTo       = angleTo,
+}