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

AGENTS.md

@@ -50,8 +50,8 @@ Conventions:
 - All imports from `/static/hoover/index.js` (barrel export of reactivity, VDOM, router, API, components).
 - Pages in `webui/static/pages/` export `definePage({ init, subscribe, load, render })` as default.
 - Bootstrap: `webui/static/app.js` mounts two render roots (`#sidebar`, `#main`), then `connect()` for WS.
-- `h()` builds VNodes; `#comp` + `hComp()` for component lifecycle; `key` for keyed diff.
-- Events use `on:` prefix (`on:click`, `on:submit`). `class` prop accepts object.
+- `h()` builds VNodes; `html` tag (from htm) enables JSX-like templates; `#comp` + `hComp()` for component lifecycle; `key` for keyed diff.
+- Events: `h()` uses `on:click` prefix. `html` templates use camelCase `onClick` (adapter translates to `on:click`).
 - State always has `loading`, `refreshing`, `error` plus data. `load()` receives `(state, abortController, entry)`.
 - `openModal` + `formModal` for dialogs; `apiSubmit()` for form submission. `ToastContainer()` in main root.
 - No build step — ES modules served raw. Assets versioned via `?v=N` query string.