refactor(warnings): report raw signal only, no severity/presentation

get_device_warnings() now returns only {code, meta} — severity, title,
message, and action are resolved centrally by netork's
WARNING_CATALOG (netork/core/device_warnings.py), not by the driver.
Keeps this driver independent of netork and avoids per-vendor drift in
how the same warning code is presented.

napalm_openwrt/system_mixin.py

@@ -501,11 +501,7 @@ class OpenWrtSystemMixin:
         # 1. LLDP daemon
         lldpd_path = self._send_command("which lldpd 2>/dev/null").strip()
         if not lldpd_path:
-            warnings.append({
-                "code": "lldpd_not_installed",
-                "severity": "warning",
-                "action": "install_lldpd",
-            })
+            warnings.append({"code": "lldpd_not_installed"})
 
         pm = self._pm_type()
 
@@ -538,8 +534,6 @@ class OpenWrtSystemMixin:
             pkg_names = [_pkg_name(ln, pm) for ln in upgradable]
             warnings.append({
                 "code": "updates_available",
-                "severity": "info",
-                "action": None,
                 "meta": {
                     "count": len(upgradable),
                     "packages": pkg_names[:10],
@@ -550,20 +544,12 @@ class OpenWrtSystemMixin:
         if pm == "opkg":
             auc_path = self._send_command("which auc 2>/dev/null").strip()
             if not auc_path:
-                warnings.append({
-                    "code": "update_notifications_disabled",
-                    "severity": "warning",
-                    "action": "install_auc",
-                })
+                warnings.append({"code": "update_notifications_disabled"})
 
         # 4. base64 not available — needed for efficient config apply
         b64_path = self._send_command("command -v base64 2>/dev/null").strip()
         if not b64_path:
-            warnings.append({
-                "code": "no_base64",
-                "severity": "warning",
-                "action": "install_coreutils_base64",
-            })
+            warnings.append({"code": "no_base64"})
 
         return warnings