Add npm package and CI workflows

The user-facing layer of the WASM port: a publishable npm package
plus the GitHub Actions that build and ship it.

* npm/package.json — publishes as `magic-vlsi-wasm`, ESM-only, HPND
  licensed, version tracks Magic's own VERSION file (8.3.637).
  Whitelists the published files and exposes index.js + index.d.ts.

* npm/index.js, npm/index.d.ts — thin JS/TS wrapper around the four
  WASM exports. createMagic(opts) returns { init, runCommand,
  sourceFile, update, FS } so consumers can write into the
  Emscripten virtual filesystem and dispatch Magic commands from
  Node.js, browsers or Web Workers.

* npm/build.sh — end-to-end build: locates emsdk (via PATH or
  EMSDK_DIR), runs distclean+configure+make in the right order
  (techs before mains so embed-files are present), copies
  magic.js / magic.wasm into npm/. Optional --release, --test,
  --pack flags. Preserves configure's exec bits across invocations.

* npm/pack.sh — produces a reproducible npm tarball by touching
  every file to the build time and exporting SOURCE_DATE_EPOCH so
  pacote does not rewrite mtimes to its 1985 fallback.

* npm/examples/ — runnable smoke tests for the four common
  workflows (extract, gds, drc, cif), driven by examples/all.js.
  Each example is self-contained and uses the bundled siliwiz
  technology. helpers.js encapsulates the boilerplate.

* npm/LICENSE, npm/README.md — license text and consumer-facing
  docs (install, quick-start, API, examples, build-from-source,
  license, third-party content notice).

* .github/workflows/main.yml — adds a `simple_build_wasm` job that
  installs a pinned emsdk (3.1.56), builds the WASM module, runs
  the example test suite and uploads the npm tarball as an
  artifact. Pinned for reproducibility against the post-build.sh
  patches; switchable to "latest" by commenting two lines.

* .github/workflows/main-aarch64.yml — drops the now-redundant
  WASM ARM job. WASM is architecture-independent.

* .github/workflows/npm-publish.yml — new workflow. Publishes to
  npm on `v*` tag pushes (manual `workflow_dispatch` supported as
  a dry-run). Uses the same pinned emsdk and pack.sh.

Also sets FORCE_JAVASCRIPT_ACTIONS_TO_NODE24 in both workflows to
silence the Node.js 20 deprecation warnings until
actions/upload-artifact@v6 ships a Node-24 release.

.github/workflows/main-aarch64.yml

@@ -1,14 +1,15 @@
-# This is a basic workflow to help you get started with Actions
+# CI for native ARM64 Linux build.
+# WASM is not built here — WebAssembly bytecode is architecture-independent,
+# so the single x86-64 WASM artifact produced by the CI workflow is identical
+# to what an ARM build would produce. See .github/workflows/main.yml.
 
 name: CI-aarch64
 
-# Controls when the workflow will run
 on:
   push:
   pull_request:
   workflow_dispatch:
 
-# A workflow run is made up of one or more jobs that can run sequentially or in parallel
 jobs:
   simple_build_linux_arm:
     runs-on: ubuntu-24.04-arm
@@ -23,39 +24,3 @@ jobs:
           ./configure
           make database/database.h
           make -j$(nproc)
-  simple_build_wasm_arm:
-    runs-on: ubuntu-24.04-arm
-    steps:
-      - uses: actions/checkout@v4
-      - name: Get Dependencies
-        run: |
-          git clone https://github.com/emscripten-core/emsdk.git
-          cd emsdk
-          ./emsdk install latest
-          ./emsdk activate latest
-      - name: Emscripten Diagnostic
-        run: |
-          source ./emsdk/emsdk_env.sh
-          echo "===== gcc -dM -E - ====="
-          echo | gcc -dM -E - | sort
-          echo "===== g++ -dM -E - ====="
-          echo | g++ -dM -E - | sort
-          echo "===== emcc -dM -E - ====="
-          echo | emcc -dM -E - | sort
-          echo "===== em++ -dM -E - ====="
-          echo | em++ -dM -E - | sort
-      - name: Build
-        run: |
-          source ./emsdk/emsdk_env.sh
-          # The --without and --disable in these build options is due to no WASM library being available for that feature
-          CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1 -g" emconfigure ./configure --without-cairo --without-opengl --without-x --without-tk --without-tcl --disable-readline --disable-compression --target=asmjs-unknown-emscripten
-          echo "===== defs.mak ====="
-          cat defs.mak
-          echo "===== defs.mak ====="
-          emmake make
-      - name: archive wasm bundle
-        uses: actions/upload-artifact@v4
-        with:
-          name: magic-wasm-bundle-arm
-          path: |
-            ${{ github.workspace }}/magic/magic.wasm

.github/workflows/main.yml

@@ -1,19 +1,21 @@
-# This is a basic workflow to help you get started with Actions
-
 name: CI
 
-# Controls when the workflow will run
 on:
   push:
   pull_request:
   workflow_dispatch:
 
-# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+# actions/upload-artifact@v5 still runs on Node.js 20. Force Node 24 to
+# silence the deprecation warning until upload-artifact ships a Node-24
+# release. Drop this once upgraded.
+env:
+  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
+
 jobs:
   simple_build_linux:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Get Dependencies
         run: |
           sudo apt-get install -y tcl-dev tk-dev libcairo-dev
@@ -24,14 +26,24 @@ jobs:
           make -j$(nproc)
   simple_build_wasm:
     runs-on: ubuntu-22.04
+    env:
+      # --- emsdk version switch ---------------------------------------------
+      # Pinned: post-build.sh patches depend on the exact text output of this
+      # Emscripten version. Bump intentionally and re-verify the patches.
+      # To test against the latest emsdk, comment the pinned line and
+      # uncomment the "latest" line below.
+      EMSDK_VERSION: '3.1.56'
+      # EMSDK_VERSION: 'latest'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Get Dependencies
         run: |
           git clone https://github.com/emscripten-core/emsdk.git
           cd emsdk
-          ./emsdk install latest
-          ./emsdk activate latest
+          ./emsdk install "$EMSDK_VERSION"
+          ./emsdk activate "$EMSDK_VERSION"
+      # Dump native + emscripten preprocessor defines. Useful for diagnosing
+      # WASM-build differences after an emsdk bump.
       - name: Emscripten Diagnostic
         run: |
           source ./emsdk/emsdk_env.sh
@@ -46,15 +58,36 @@ jobs:
       - name: Build
         run: |
           source ./emsdk/emsdk_env.sh
-          # The --without and --disable in these build options is due to no WASM library being available for that feature
-          CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1 -g" emconfigure ./configure --without-cairo --without-opengl --without-x --without-tk --without-tcl --disable-readline --disable-compression --target=asmjs-unknown-emscripten
+          # --without/--disable flags: no WASM library available for these features
+          CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1 -g" emconfigure ./configure \
+            --without-cairo --without-opengl --without-x --without-tk --without-tcl \
+            --disable-readline --disable-compression \
+            --host=asmjs-unknown-emscripten \
+            --target=asmjs-unknown-emscripten
+          # Append WASM linker flags and activate the WASM link target
+          cat toolchains/emscripten/defs.mak >> defs.mak
+          # Echo the merged defs.mak so CI logs show the exact build config
           echo "===== defs.mak ====="
           cat defs.mak
           echo "===== defs.mak ====="
-          emmake make
-      - name: archive wasm bundle
-        uses: actions/upload-artifact@v4
+          # Build in order: techs must exist before mains (--embed-file embeds them)
+          emmake make depend
+          emmake make -j$(nproc) modules libs
+          emmake make techs
+          emmake make mains
+      - name: Set up Node.js
+        uses: actions/setup-node@v5
         with:
-          name: magic-wasm-bundle
-          path: |
-            ${{ github.workspace }}/magic/magic.wasm
+          node-version: '22'
+      - name: Run example tests
+        run: |
+          cp magic/magic.js  npm/
+          cp magic/magic.wasm npm/
+          cd npm && npm run test
+      - name: Pack npm package
+        run: ./npm/pack.sh
+      - name: Upload npm package
+        uses: actions/upload-artifact@v5
+        with:
+          name: magic-vlsi-wasm-npm
+          path: ${{ github.workspace }}/npm/*.tgz

.github/workflows/npm-publish.yml

@@ -0,0 +1,95 @@
+name: Publish npm package
+
+# Publishes magic-vlsi-wasm to npm.
+# Triggered automatically on version tags (v*); can also be run manually.
+# Requires an NPM_TOKEN repository secret for publishing.
+#
+# WASM is architecture-independent — built once on x86-64, usable everywhere.
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        description: 'Dry run: pack only, do not publish'
+        type: boolean
+        default: true
+
+# actions/upload-artifact@v5 still runs on Node.js 20. Force Node 24 to
+# silence the deprecation warning until upload-artifact ships a Node-24
+# release. Drop this once upgraded.
+env:
+  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-22.04
+
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v5
+        with:
+          node-version: '22'
+          registry-url: 'https://registry.npmjs.org'
+
+      - name: Install emsdk
+        env:
+          # --- emsdk version switch -----------------------------------------
+          # Pinned: must match .github/workflows/main.yml. See post-build.sh.
+          # To test against the latest emsdk, comment the pinned line and
+          # uncomment the "latest" line below.
+          EMSDK_VERSION: '3.1.56'
+          # EMSDK_VERSION: 'latest'
+        run: |
+          git clone https://github.com/emscripten-core/emsdk.git
+          cd emsdk
+          ./emsdk install "$EMSDK_VERSION"
+          ./emsdk activate "$EMSDK_VERSION"
+
+      - name: Build WASM
+        run: |
+          source ./emsdk/emsdk_env.sh
+          # --without/--disable flags: no WASM library available for these features
+          CFLAGS="--std=c17 -D_DEFAULT_SOURCE=1 -DEMSCRIPTEN=1" emconfigure ./configure \
+            --without-cairo --without-opengl --without-x --without-tk --without-tcl \
+            --disable-readline --disable-compression \
+            --host=asmjs-unknown-emscripten \
+            --target=asmjs-unknown-emscripten
+          # Append WASM linker flags and activate the WASM link target
+          cat toolchains/emscripten/defs.mak >> defs.mak
+          # Build in order: techs must exist before mains (--embed-file embeds them)
+          emmake make depend
+          emmake make -j$(nproc) modules libs
+          emmake make techs
+          emmake make mains
+
+      - name: Copy WASM artifacts into npm/
+        run: |
+          cp magic/magic.js  npm/
+          cp magic/magic.wasm npm/
+
+      - name: Set package version from tag
+        if: startsWith(github.ref, 'refs/tags/v')
+        run: |
+          VERSION="${GITHUB_REF#refs/tags/v}"
+          cd npm
+          npm version "$VERSION" --no-git-tag-version
+
+      - name: Pack
+        run: ./npm/pack.sh
+
+      - name: Upload tarball as artifact
+        uses: actions/upload-artifact@v5
+        with:
+          name: magic-wasm-npm-package
+          path: npm/*.tgz
+
+      - name: Publish to npm
+        if: startsWith(github.ref, 'refs/tags/v') && github.event.inputs.dry_run != 'true'
+        run: cd npm && npm publish --access public
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}