Phase 3: Svelte 5 UI skeleton

Svelte 5 + Vite + TypeScript dashboard that consumes kamado-api over
REST for the first paint and then subscribes to /api/ws for live
updates. Zero runtime deps beyond svelte itself; plain CSS, no
component library.

Layout:

- Header with brand, WebSocket status badge, chain + height
- PoolOverview: hashrate (1m/5m/1h/24h), miner count, network
  hashrate + diff, pool share (ppb), expected time to block, uptime
- BlocksTable: recent solves from the in-memory ring (will be
  SQLite-backed in Phase 2b.5)
- BestShares: top-10 workers by bestever, falling back to bestdiff
  when the ckpool patch isn't present
- MinersTable: joined view of stratum clients and workers with
  user-agent-based hardware detection (Bitaxe, NerdQAxe, Antminer,
  ...), hashrate, best-round, best-ever, last share

State is a single $state() snapshot store in svelte-runes form;
components read from it via $derived. The store does one initial
REST snapshot fetch, then owns the WebSocket with exponential
backoff reconnects.

Vite dev server on :5173 proxies /api and /api/ws to localhost:8080
so you can run `make ui-dev` alongside `make up` in development.
Production serving (bundled into the Go binary via embed, behind /
on :8080) lands in Phase 4.

README.md

@@ -42,7 +42,8 @@ Three main components:
     - [x] Phase 2a: CKPool socket client, bitcoind RPC, state aggregator, REST API
     - [x] Phase 2b: CKPool log tailer, block history, stdlib WebSocket push
     - [ ] Phase 2b.5: ZMQ block notifier, SQLite persistence (deferred until s9pk repo exists — need real Go build env for new deps)
-- [ ] **Phase 3** — Svelte UI dashboard
+- [x] ckpool patch 0001: expose `bestever` in runtime socket JSON so the UI can show "this round" and "all-time" best share side by side
+- [~] **Phase 3** — Svelte UI dashboard (skeleton: header, pool overview, miners table, blocks, best shares leaderboard; live WS updates)
 - [ ] **Phase 4** — Monorepo Docker build, full stack integration
 - [ ] **Phase 5** — Testing (regtest, testnet4), polish