[eric] onboarding bug fix and ux op

scripts/build-app.sh

@@ -346,6 +346,19 @@ else
 fi
 echo ""
 
+# Step 3c: Pre-build the webapp-template node_modules archive so first-app
+# create on a fresh user install decompresses (~3 s) instead of running a
+# live `npm install` (~22 s). The backend's _try_extract_bundled_archive
+# is sha-tagged + falls through cleanly if the archive is missing or
+# stale, so this step is purely an optimization — skip silently if the
+# template snapshot or npm aren't available.
+if [[ -f "$PROJECT_ROOT/backend/apps/outputs/webapp_template/frontend/package.json" ]] \
+   && command -v npm >/dev/null 2>&1; then
+    echo "[3c/5] Pre-building webapp-template node_modules archive..."
+    bash "$PROJECT_ROOT/scripts/build-template-archive.sh"
+    echo ""
+fi
+
 # Step 4: Snapshot source directories for packaging
 # (Router was already staged in step 3; do not touch STAGING_DIR/router/ here.)
 echo "[4/5] Snapshotting source directories..."

scripts/build-template-archive.sh

@@ -0,0 +1,80 @@
+#!/bin/bash
+# Build the pre-compressed webapp-template node_modules archive that gets
+# bundled into signed releases. Backend code (_try_extract_bundled_archive
+# in view_builder_templates.py) unpacks this on first-app create instead
+# of running a live `npm install`, dropping cold-start ~22 s → ~3 s.
+#
+# Run this once before packaging (CI / publish.sh / publish-win.ps1).
+# Local dev installs that skip this step transparently fall through to
+# live `npm install` — the archive is purely an optimization.
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+TEMPLATE_DIR="$PROJECT_ROOT/backend/apps/outputs/webapp_template"
+OUT_DIR="$PROJECT_ROOT/backend/apps/outputs/webapp_template_cache"
+
+if [[ ! -f "$TEMPLATE_DIR/frontend/package.json" ]]; then
+    echo "ERROR: $TEMPLATE_DIR/frontend/package.json not found"
+    echo "Run scripts/fetch-webapp-template.sh first to populate the template."
+    exit 1
+fi
+
+# Tag the archive with a sha of package.json so a stale archive from a
+# previous template version is automatically skipped at runtime (the
+# backend's _bundled_archive_path_for() computes the same digest). The
+# 12-char prefix mirrors view_builder_templates._warm_cache_digest().
+if command -v shasum >/dev/null 2>&1; then
+    PKG_DIGEST=$(shasum -a 256 "$TEMPLATE_DIR/frontend/package.json" | awk '{print substr($1,1,12)}')
+elif command -v sha256sum >/dev/null 2>&1; then
+    PKG_DIGEST=$(sha256sum "$TEMPLATE_DIR/frontend/package.json" | awk '{print substr($1,1,12)}')
+else
+    echo "ERROR: neither shasum nor sha256sum found on PATH"
+    exit 1
+fi
+OUT_ARCHIVE="$OUT_DIR/node_modules.${PKG_DIGEST}.tar.gz"
+
+# Work in a temp dir so a failed install can't corrupt the template tree.
+WORK_DIR=$(mktemp -d -t openswarm-template-archive-XXXXXX)
+trap "rm -rf '$WORK_DIR'" EXIT
+
+echo "Building template node_modules archive..."
+echo "  source : $TEMPLATE_DIR/frontend/"
+echo "  digest : $PKG_DIGEST"
+echo "  staging: $WORK_DIR"
+echo "  output : $OUT_ARCHIVE"
+echo ""
+
+cp "$TEMPLATE_DIR/frontend/package.json" "$WORK_DIR/package.json"
+if [[ -f "$TEMPLATE_DIR/frontend/package-lock.json" ]]; then
+    cp "$TEMPLATE_DIR/frontend/package-lock.json" "$WORK_DIR/package-lock.json"
+    cd "$WORK_DIR"
+    echo "[npm] running npm ci..."
+    npm ci --prefer-offline --no-audit --no-fund --loglevel=error
+else
+    cd "$WORK_DIR"
+    echo "[npm] running npm install (no lockfile)..."
+    npm install --prefer-offline --no-audit --no-fund --loglevel=error
+fi
+
+if [[ ! -d "$WORK_DIR/node_modules" ]]; then
+    echo "ERROR: npm did not produce node_modules in $WORK_DIR"
+    exit 1
+fi
+
+mkdir -p "$OUT_DIR"
+echo ""
+echo "[tar] compressing node_modules..."
+# `tar -C "$WORK_DIR" node_modules` so the archive root is `node_modules/`,
+# matching what _try_extract_bundled_archive expects when extracting into
+# cache_dir.
+tar -czf "$OUT_ARCHIVE" -C "$WORK_DIR" node_modules
+
+ARCHIVE_SIZE=$(du -h "$OUT_ARCHIVE" | awk '{print $1}')
+NM_FILES=$(find "$WORK_DIR/node_modules" -type f | wc -l | tr -d ' ')
+echo ""
+echo "Done."
+echo "  archive   : $OUT_ARCHIVE"
+echo "  size      : $ARCHIVE_SIZE"
+echo "  files in  : $NM_FILES"