Add El source files for all client-side JS

Recovers original JS from git history and ports it into proper El source
files under src/js/. Each file wraps the original JS in a native_js call
inside a main() function, making it valid El that compiles to a
self-contained IIFE via elc --target=js --bundle.

Files added:
  src/js/account-auth.el       - Supabase OTP magic-link (sendMagicLink)
  src/js/account-dashboard.el  - Account dashboard: session, plan card, family
  src/js/chat-widget.el        - Demo chat widget (neuronDemoToggle/Send/Reset)
  src/js/checkout-auth.el      - Checkout auth: OAuth, email sign-in/up
  src/js/checkout-free.el      - Free plan: auth-badge watch -> payment reveal
  src/js/checkout-stripe.el    - Stripe Payment Element (reads NEURON_CFG)
  src/js/enterprise.el         - Enterprise inquiry form + headcount filter
  src/js/environmental.el      - Efficiency calculator slider
  src/js/gallery.el            - Gallery nav, search/sort, Supabase voting
  src/js/main.el               - Share page voting + copyForPlatform
  src/js/marketplace.el        - Developer interest form
  src/js/nav.el                - Nav hamburger + Mission dropdown
  src/js/styles.el             - Landing: nav scroll, reveal, founding counter

build-stage.sh

@@ -4,23 +4,22 @@
 #
 # Pipeline:
 #   1. Stage the foundation El runtime into ./runtime/.
-#   2. Concatenate src/*.el into dist/main-combined.el (component-first,
+#   2. Compile client-side El sources (src/js/*.el) to dist/js/*.js using
+#      the JS-capable elc binary at bin/elc-linux-amd64 (CI) or the local
+#      elc (dev). Output is gitignored and rebuilt every run.
+#   3. Concatenate src/*.el into dist/main-combined.el (component-first,
 #      main.el last; matches the historical order from build-local.sh).
-#   3. Compile dist/main-combined.el → dist/main.c using the canonical
+#   4. Compile dist/main-combined.el → dist/main.c using the canonical
 #      native elc at foundation/el/dist/platform/elc.
-#   4. Inject the host-side stub forward declarations into dist/main.c
+#   5. Inject the host-side stub forward declarations into dist/main.c
 #      (sed header rewrite, same set as the prior in-Dockerfile sed).
-#   5. docker buildx build --platform linux/amd64 -f Dockerfile.stage.
+#   6. docker buildx build --platform linux/amd64 -f Dockerfile.stage.
 #
 # bootstrap.py is no longer in the build path. The container image now
 # expects dist/main.c to be a finished C source — it just runs cc on it.
 #
-# Inline-JS extraction is gated by EXTRACT_JS=1 just like build-local.sh
-# was. Production deploys should always extract.
-#
 # Usage:
 #   ./build-stage.sh <tag>           — build marketing:<tag>
-#   EXTRACT_JS=1 ./build-stage.sh X  — also extract inline JS to assets
 
 set -euo pipefail
 cd "$(dirname "$0")"
@@ -32,6 +31,17 @@ EL_HOME="${EL_HOME:-${LANDING_DIR}/../../foundation/el}"
 ELC="${EL_HOME}/dist/platform/elc"
 RUNTIME_SRC="${EL_HOME}/el-compiler/runtime"
 
+# JS-capable elc: prefer committed bin/elc-linux-amd64 on CI (linux/amd64),
+# fall back to the local elc from the El checkout on macOS dev.
+if [ -f "${LANDING_DIR}/bin/elc-linux-amd64" ] && uname -m | grep -q x86_64; then
+    ELC_JS="${LANDING_DIR}/bin/elc-linux-amd64"
+elif [ -x "${ELC}" ]; then
+    ELC_JS="${ELC}"
+else
+    echo "elc for JS compilation not found — expected bin/elc-linux-amd64 or ${ELC}" >&2
+    exit 1
+fi
+
 if [ ! -x "${ELC}" ]; then
     echo "elc not found at ${ELC}" >&2
     exit 1
@@ -42,17 +52,20 @@ mkdir -p runtime dist
 cp "${RUNTIME_SRC}/el_runtime.c" runtime/
 cp "${RUNTIME_SRC}/el_runtime.h" runtime/
 
-# Optional inline-JS extraction. Off by default for fast dev iteration; the
-# script is idempotent so flipping the flag on a prior tree just reuses
-# previously-extracted assets.
-if [[ "${EXTRACT_JS:-0}" == "1" ]]; then
-    echo "==> Extracting inline JS → src/assets/js/"
-    if [ ! -x "node_modules/.bin/terser" ] || [ ! -x "node_modules/.bin/javascript-obfuscator" ]; then
-        echo "    installing terser + javascript-obfuscator (no-save)..."
-        npm install --no-save --silent terser javascript-obfuscator
-    fi
-    python3 scripts/extract-js.py
-fi
+# The JS compiler looks for el_runtime.js in the same directory as the
+# source file being compiled. Copy it there so --bundle can inline it.
+cp "${RUNTIME_SRC}/el_runtime.js" "${LANDING_DIR}/src/js/"
+
+echo "==> Compiling client-side El (src/js/*.el) → dist/js/"
+mkdir -p dist/js
+for f in "${LANDING_DIR}/src/js/"*.el; do
+    name=$(basename "$f" .el)
+    "${ELC_JS}" --target=js --bundle --minify --obfuscate "$f" > "${LANDING_DIR}/dist/js/${name}.js"
+    echo "    compiled: src/js/${name}.el → dist/js/${name}.js"
+done
+
+# Clean up the staged runtime (not a source file)
+rm -f "${LANDING_DIR}/src/js/el_runtime.js"
 
 echo "==> Combining El sources → dist/main-combined.el"
 COMPONENTS=(nav hero pillars how_it_works inference efficiency comparison