Alerts tab, Docker tab, nine new skins including HUD, a colour for every machine

Alerts: rules over sensors, watched fleet-wide from the hub; ntfy and webhook channels;
firing count on the rail. Docker: containers by stack with live use, start/stop/restart,
following logs, inspect, images/volumes/networks. Skins: HUD, Nord, Gruvbox, Catppuccin
(+Latte), Dracula, Tokyo Night, Solarized (+Light). Accents: per-machine colour.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

web/src/Settings.tsx

@@ -1,6 +1,7 @@
 import { FormEvent, useCallback, useEffect, useState } from 'react'
 import { fetchCatalog } from './sensors'
 import { api, Me } from './api'
+import { savePrefs } from './accents'
 import { applyTheme, currentThemeId, THEMES } from './themes'
 import { Btn, Loading, askYes, toast, useEscape } from './ui'
 import { fmtMs, getRefreshMs, REFRESH_OPTIONS, setRefreshMs } from './prefs'
@@ -45,11 +46,11 @@ export default function Settings({ me }: { me: Me }) {
 
   const pick = async (id: string) => {
     applyTheme(id); setTheme(id)
-    try { await api.saveUIPrefs({ theme: id, refreshMs: getRefreshMs() }) } catch { /* local still applied */ }
+    await savePrefs()
   }
   const pickRefresh = async (ms: number) => {
     setRefreshMs(ms); setRefresh(ms)
-    try { await api.saveUIPrefs({ theme: currentThemeId(), refreshMs: ms }) } catch { /* local still applied */ }
+    await savePrefs()
   }
 
   async function changePassword(e: FormEvent) {