Track the vendored PicoRuby artifacts in git

The wasm builds (dist/debug), mrbc, and picoruby-test-node used to be
populated only at gem build time, so a git checkout was not equivalent
to the packaged gem: consumers riding master via path/git references
(the dogfooding app's CI above all) had no way to run. All artifacts
are wasm, so there is no platform matrix to track, and each directory
carries a VERSION file for provenance.

The rebuild ritual now includes committing the refreshed artifacts
verbatim (emscripten output keeps its trailing whitespace; the
pre-commit whitespace check is skipped for artifact refreshes).
History now pairs every mrblib change with the wasm that embeds it,
which also retires the "ships with the next rebuild" bookkeeping.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: hasumikin

.gitignore

@@ -8,10 +8,4 @@
 /tmp/
 *.gem
 
-# Vendored PicoRuby.wasm and picorbc artifacts are populated by
-# `rake funicular:vendor` at gem build time; they ship in the released gem
-# but are not tracked here.
-/lib/funicular/vendor/picoruby-test-node/
-/lib/funicular/vendor/picoruby/
-/lib/funicular/vendor/mrbc/
 private_docs/

lib/funicular/vendor/mrbc/VERSION

@@ -0,0 +1 @@
+4.0.3