fix: npm ci hangs — clean node_modules, add timeout, install build-essential

- rm -rf node_modules before npm ci (clean from aborted runs)
- 420s timeout on npm ci (kills if stuck on native module compilation)
- Install build-essential + python3 for better-sqlite3 native addon
- Exit with clear error if npm ci fails

install.sh

@@ -138,13 +138,29 @@ log "Data directory ready"
 
 STANDALONE_DIR="$INSTALL_DIR/.next/standalone"
 
+# ── Build dependencies (build-essential for native modules) ──
+if ! command -v g++ &>/dev/null; then
+  info "Installing build tools (needed for native modules)..."
+  case "$OS" in
+    ubuntu|debian)          sudo apt install -y -qq build-essential python3 ;;
+    arch|endeavouros)       sudo pacman -S --noconfirm base-devel python ;;
+    fedora|centos|rhel|*)   sudo dnf groupinstall -y "Development Tools" && sudo dnf install -y python3 ;;
+  esac
+  log "Build tools installed"
+fi
+
 # ── Build (skip if already built) ──────────────────
 if [ -f "$STANDALONE_DIR/server.js" ]; then
   info "Build already exists — skipping"
 else
-  info "Installing npm dependencies..."
+  info "Installing npm dependencies (may take 1-5 min)..."
   cd "$INSTALL_DIR"
-  npm ci
+  rm -rf node_modules 2>/dev/null || true
+  if ! timeout 420 npm ci 2>&1; then
+    err "npm ci failed. Check npm registry access or try manually:"
+    err "  cd $INSTALL_DIR && npm ci"
+    exit 1
+  fi
   log "Dependencies installed"
 
   info "Building Next.js app (this may take a few minutes)..."