feat: enhance systemd unit and install script for browser dependencies

Updated the systemd unit generation to include the virtual environment and node modules in the PATH, improving the execution context for the hermes CLI. Additionally, added support for installing Playwright and its dependencies on Arch/Manjaro systems in the install script, ensuring a smoother setup process for browser tools.

hermes_cli/gateway.py

@@ -157,6 +157,12 @@ def generate_systemd_unit() -> str:
     import shutil
     python_path = get_python_path()
     working_dir = str(PROJECT_ROOT)
+    venv_dir = str(PROJECT_ROOT / "venv")
+    venv_bin = str(PROJECT_ROOT / "venv" / "bin")
+    node_bin = str(PROJECT_ROOT / "node_modules" / ".bin")
+
+    # Build a PATH that includes the venv, node_modules, and standard system dirs
+    sane_path = f"{venv_bin}:{node_bin}:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
     
     hermes_cli = shutil.which("hermes") or f"{python_path} -m hermes_cli.main"
     return f"""[Unit]
@@ -168,6 +174,8 @@ Type=simple
 ExecStart={python_path} -m hermes_cli.main gateway run --replace
 ExecStop={hermes_cli} gateway stop
 WorkingDirectory={working_dir}
+Environment="PATH={sane_path}"
+Environment="VIRTUAL_ENV={venv_dir}"
 Restart=on-failure
 RestartSec=10
 KillMode=mixed

scripts/install.sh

@@ -829,6 +829,33 @@ install_node_deps() {
             log_warn "npm install failed (browser tools may not work)"
         }
         log_success "Node.js dependencies installed"
+
+        # Install Playwright browser + system dependencies.
+        # Playwright's install-deps only supports apt/dnf/zypper natively.
+        # For Arch/Manjaro we install the system libs via pacman first.
+        log_info "Installing browser engine (Playwright Chromium)..."
+        case "$DISTRO" in
+            arch|manjaro)
+                if command -v pacman &> /dev/null; then
+                    log_info "Arch/Manjaro detected — installing Chromium system dependencies via pacman..."
+                    if command -v sudo &> /dev/null && sudo -n true 2>/dev/null; then
+                        sudo NEEDRESTART_MODE=a pacman -S --noconfirm --needed \
+                            nss atk at-spi2-core cups libdrm libxkbcommon mesa pango cairo alsa-lib >/dev/null 2>&1 || true
+                    elif [ "$(id -u)" -eq 0 ]; then
+                        pacman -S --noconfirm --needed \
+                            nss atk at-spi2-core cups libdrm libxkbcommon mesa pango cairo alsa-lib >/dev/null 2>&1 || true
+                    else
+                        log_warn "Cannot install browser deps without sudo. Run manually:"
+                        log_warn "  sudo pacman -S nss atk at-spi2-core cups libdrm libxkbcommon mesa pango cairo alsa-lib"
+                    fi
+                fi
+                cd "$INSTALL_DIR" && npx playwright install chromium 2>/dev/null || true
+                ;;
+            *)
+                cd "$INSTALL_DIR" && npx playwright install --with-deps chromium 2>/dev/null || true
+                ;;
+        esac
+        log_success "Browser engine installed"
     fi
 
     # Install WhatsApp bridge dependencies

tools/browser_tool.py

@@ -815,6 +815,13 @@ def _run_browser_command(
             level = logging.WARNING if result.returncode != 0 else logging.DEBUG
             logger.log(level, "browser '%s' stderr: %s", command, result.stderr.strip()[:500])
         
+        # Log empty output as warning — common sign of broken agent-browser
+        if not result.stdout.strip() and result.returncode == 0:
+            logger.warning("browser '%s' returned empty stdout with rc=0. "
+                           "cmd=%s stderr=%s",
+                           command, " ".join(cmd_parts[:4]) + "...",
+                           (result.stderr or "")[:200])
+
         # Parse JSON output
         if result.stdout.strip():
             try: