Add state management, WebSocket polling, html.js templating, and refactor pages

- lib/state.py: per-subsystem collectors with versioned state store
- daemon/server.py: state refresh on request, batch routing updates
- webui/static/hoover/html.js: new html tag template helper via htm.js
- webui/static/hoover/websocket.js: real-time state change notifications
- webui/static/hoover/vdom.js: VDOM improvements for keyed diff
- All frontend pages refactored to use html templates
- Add tests for state management and polling
- Update docs and AGENTS.md

webui/static/hoover/components/modal.js

@@ -9,6 +9,20 @@
 import { esc } from '../helpers.js?v=7';
 import { att_esc } from '../helpers.js?v=7';
 import { apiSubmit } from '../api.js?v=7';
+import { createDom } from '../vdom.js?v=7';
+
+/**
+ * Render Hoover VNodes into a modal content element.
+ * VDOM is not diffed across modal re-render — modals are transient and
+ * innerHTML is cleared/repainted each time (avoids lifecycle baggage).
+ */
+export function modalVNodes(inner, vnodes) {
+    inner.innerHTML = '';
+    const nodes = Array.isArray(vnodes) ? vnodes : [vnodes];
+    for (const vnode of nodes) {
+        if (vnode) inner.appendChild(createDom(vnode));
+    }
+}
 
 const _modalQueue = [];
 
@@ -35,10 +49,15 @@ function _renderModals() {
 /**
  * Open a modal dialog.
  *
- * @param {function} renderFn – (contentEl, idx) => void, renders into contentEl
+ * @param {function|object} content – Either:
+ *   - renderFn(contentEl, idx) => void  (legacy innerHTML path)
+ *   - VNode / VNode[]                  (new VDOM path — uses modalVNodes)
  */
-export function openModal(renderFn) {
-    _modalQueue.push({ renderFn, id: _modalQueue.length });
+export function openModal(content) {
+    const entry = typeof content === 'function'
+        ? { renderFn: content, id: _modalQueue.length }
+        : { id: _modalQueue.length, renderFn: (inner) => modalVNodes(inner, content) };
+    _modalQueue.push(entry);
     _renderModals();
 }
 
@@ -61,6 +80,11 @@ export function closeAllModals() {
     _renderModals();
 }
 
+/** Re-render all open modals. Used by long-lived modals that update in place. */
+export function refreshModals() {
+    _renderModals();
+}
+
 /**
  * Render a standard modal layout: title, form fields, action buttons.
  *