refactor: introduce model layer for centralized data synchronization

Add hoover model.js as a central reactive store per subsystem, replacing
per-component data fetching with a single source of truth.

- Add hoover/model.js with modelRegister, modelFetch, and WS invalidation
- Refactor websocket.js to route messages to model refresh (drop per-component
  subscribe/unsubscribe)
- Simplify component.js by removing WS subscription management
- Add refresh option to apiSubmit, deprecate refactorLoad and checkAbort
- Rewrite all pages to use getModel() instead of inline data fetching
- Bootstrap model registrations in app.js
- Add GET /api/firewall/state endpoint
- Fix restart-services.sh restart order and add service health verification
- Update hoover.md docs with model layer architecture

webui/static/pages/proxy.js

@@ -1,4 +1,4 @@
-import { h, PageHeader, Badge, Empty, Table, renderGuard, esc, enc, $val, apiFetch, toast, definePage, refactorLoad, ActionButton, ActionCell, certStatusBadge, ActionGroup, QuickModal } from '/static/hoover/index.js?v=6';
+import { h, PageHeader, Badge, Empty, Table, renderGuardMulti, esc, enc, $val, apiFetch, toast, definePage, getModel, modelFetch, ActionButton, ActionCell, certStatusBadge, ActionGroup, QuickModal } from '/static/hoover/index.js?v=7';
 
 const addDomain = QuickModal({
     title: 'Add Proxy Domain',
@@ -21,7 +21,7 @@ const addDomain = QuickModal({
         validate: (b) => !b.domain || !b.backend_host || !b.backend_port ? 'Domain, host, and port are required' : null,
         successMsg: 'Domain added',
     },
-    reload: (s) => load(s),
+    refresh: ['nginx', 'acme'],
 });
 
 const editDomain = QuickModal({
@@ -35,7 +35,7 @@ const editDomain = QuickModal({
     submit: {
         url: (d) => '/api/proxy/domains/' + enc(d.domain),
         method: 'PUT',
-        body: (d) => ({
+        body: () => ({
             backend_host: ($val('pe-host') || '').trim(),
             backend_port: parseInt($val('pe-port')),
             backend_proto: ($val('pe-proto') || 'http').trim(),
@@ -44,37 +44,22 @@ const editDomain = QuickModal({
         validate: (b) => !b.backend_host || !b.backend_port ? 'Host and port are required' : null,
         successMsg: 'Domain updated',
     },
-    reload: (s) => load(s._s),
+    refresh: ['nginx', 'acme'],
 });
 
-async function load(state, abortController, entry) {
-    await refactorLoad(state,
-        s => s.domains?.length,
-        async (s, sig, isAborted) => {
-            const domainsR = await apiFetch('/api/proxy/domains', { signal: sig });
-            if (isAborted()) return;
-            if (domainsR.ok) s.domains = domainsR.data || [];
-            else s.error = domainsR.error;
-            const certsR = await apiFetch('/api/certs/list', { signal: sig });
-            if (isAborted()) return;
-            if (certsR.ok) s.certs = certsR.data || [];
-            else if (!s.error) s.error = certsR.error;
-        },
-        { entry, abortController },
-    );
-}
-
 export default definePage({
     init() {
-        return { domains: [], certs: [] };
+        return {
+            nginx: getModel('nginx'),
+            acme: getModel('acme'),
+        };
     },
-    subscribe: ['nginx', 'acme'],
-    load,
     render(state) {
-        const guard = renderGuard(state, 'Proxy', 'Nginx reverse proxy', state.domains);
+        const guard = renderGuardMulti('Proxy', 'Nginx reverse proxy', state.nginx, state.acme);
         if (guard) return guard;
 
-        const rows = state.domains.map(d => {
+        const domains = state.nginx.data || [];
+        const rows = domains.map(d => {
             const certBadge = certStatusBadge({
                 certStatus: d.cert_status,
                 daysRemaining: d.days_remaining,
@@ -89,11 +74,11 @@ export default definePage({
                 h('td', null, certBadge),
                 ActionCell({
                     editLabel: 'Edit',
-                    editClick: () => editDomain({ ...d, _s: state }),
+                    editClick: () => editDomain(d),
                     removeUrl: '/api/proxy/domains/' + enc(d.domain),
                     removeMessage: 'Remove proxy for ' + d.domain + '?',
                     removeSuccess: 'Domain removed',
-                    removeReload: () => load(state),
+                    removeRefresh: ['nginx', 'acme'],
                     removeLabel: 'Delete',
                 }),
             );
@@ -105,7 +90,7 @@ export default definePage({
                 url: '/api/proxy/apply',
                 successMsg: 'Nginx applied & reloaded',
                 label: 'Apply',
-                reload: () => load(state),
+                refresh: ['nginx', 'acme'],
             }),
         );
 
@@ -119,4 +104,4 @@ export default definePage({
                 : Empty({ text: 'No proxy domains configured. Add a domain to start terminating SSL.' }),
         ];
     },
-});
+});