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/README.md

@@ -0,0 +1,52 @@
+# json4lua
+JSON and JSONRPC for Lua
+
+# Installation #
+```
+luarocks install --server=http://rocks.moonscript.org/manifests/amrhassan --local json4Lua
+```
+
+# JSON Usage #
+
+## Encoding ##
+
+```lua
+json = require('json')
+print(json.encode({ 1, 2, 'fred', {first='mars',second='venus',third='earth'} }))
+```
+```json
+[1,2,"fred", {"first":"mars","second":"venus","third":"earth"}]
+```
+
+## Decoding ##
+
+```lua
+json = require("json")
+testString = [[ { "one":1 , "two":2, "primes":[2,3,5,7] } ]]
+decoded = json.decode(testString)
+table.foreach(decoded, print)
+print ("Primes are:")
+table.foreach(decoded.primes,print)
+```
+```
+one		1
+two		2
+primes		table: 0032B928
+Primes are:
+1		2
+2		3
+3		5
+4		7
+```
+
+# JSONRPC Usage #
+```lua
+json = require('json')
+require("json.rpc")
+server = json.rpc.proxy("http://jsolait.net/testj.py")
+result, error = server.echo('Test echo!')
+print(result)
+```
+```
+Test echo!
+```