web-ui(wave 2): migrate home.html to new primitives
Swap stylesheet to /dist/app.css. Sidebar markup ported to wd-sidebar /
wd-nav-item / wd-sidebar-* primitives (active state = leading accent dot).
Logout button promoted to wd-btn--ghost--sm--icon.
Hero (portrait, wordmark, tagline) and the 10 illustrated cards keep
their bespoke design — they're a brand moment. Hardcoded oklch values
in the inline style replaced with var(--accent-bright), var(--signal-bad),
var(--bg-base), var(--accent-border), var(--overlay), etc. wherever the
brand palette already provides them.
All JS ids preserved (assetCount, projectCount, recorderCount,
containerCount, nodeCount, jobCount, ingestCount, captureStatus,
tokenBurn, userAvatar, userName, userRole, logoutBtn, systemBuild).
loadStats() poll cycle unchanged.