fix: remove remaining intubun/tcl references and dead workflow comment

Replace the last three intubun/tcl mentions with tcltk/tcl in
npm/tcl.js, toolchains/emscripten/build-tcl-wasm.sh, and npm/tcl.ref.
Also remove the stale comment in tcl.ref that referenced a non-existent
update-tcl GitHub Actions workflow.

npm/tcl.js

@@ -1,7 +1,7 @@
 // TCL-enabled entry point: import from "magic-vlsi-wasm/tcl".
 //
 // In this variant magic.wasm embeds a full Tcl 9 interpreter (from
-// intubun/tcl, pinned via magic/npm/tcl.ref) and `runCommand(str)` calls
+// tcltk/tcl, pinned via magic/npm/tcl.ref) and `runCommand(str)` calls
 // Tcl_EvalEx(magicinterp, str, ...).  Pure Tcl works:
 //
 //     await magic.runCommand('set x 42');

npm/tcl.ref

@@ -7,10 +7,6 @@
 #   1. Update TCL_REF below to the desired commit SHA (or tag/branch).
 #   2. Bump magic/VERSION as usual.
 #   3. Commit + push. CI rebuilds and republishes.
-#
-# Or use the `update-tcl` GitHub Actions workflow (workflow_dispatch only) to
-# fetch a target ref from intubun/tcl and open a PR that just rewrites this
-# file — you review and merge.
 
 TCL_REPO_URL=https://github.com/tcltk/tcl.git
 TCL_REF=84b23291b0dd811d642abef4ec7a55473c3eccb3

toolchains/emscripten/build-tcl-wasm.sh

@@ -16,7 +16,7 @@
 #
 # Requirements: an activated emsdk (emcc/emconfigure/emmake on PATH), a host
 # gcc (used to build TCL's minizip helper, which runs natively), make, and a
-# git checkout of intubun/tcl pointed to by --src.
+# git checkout of tcltk/tcl pointed to by --src.
 #
 # Note on line endings: if the TCL source tree was cloned on Windows with
 # git's core.autocrlf=true, unix/configure may have CRLF line endings and