feat(web): reshape workshop from 'tune a harness' to 'design a domain node'

The board is now a Claude-powered ZeroClaw agent with expert skills that teams
talk to directly (its own dashboard / Telegram / voice). The frontend was built
on the older sensor+harness model; this repoints it.

- State/DTO: AddLayers remapped to the 5 design layers (Domain/Skills/Policies/
  Harness/Loops); added session.domain (+ mirrored through TeamSnapshot, sync,
  and the SQLite store with a guarded migration); dropped Harness/Provider/RunMode;
  persist v2 migrate resets stale state.
- Removed the harness/sim/failover machinery (HarnessProviderSelect, HarnessTuner,
  HarnessTomlPreview, ResiliencePanel, TriggerButtons, harness.ts, useSerial,
  LiveFeed/serial classifier) and every sim-vs-live branch.
- Onboarding: EnvSetup rebuilt into 'Meet your node' — Open-your-node hero (new
  reusable OpenYourNode CTA), say-hi-to-your-agent, a free-text DomainPicker
  (domain drives L1-L5), Telegram/voice pointers, and the open->locked lockdown
  policy step. Domain is required to proceed.
- Modules repointed: M1 Domain & events (L1), M2 Skills & Policies (L2/L3, skills
  reference + actuation-gate framing), M3 Harness (reasoning+tiering) & Loops
  (cadence) (L4/L5). BuildFlash reframed as a guided 'ask your node to build X'
  that hands off to the node dashboard.
- Judge rubric -> Domain fit/Skills/Policies/Harness/Loops; Lecture + Landing
  re-storied to the Claude-node + talk-to-your-node narrative.

Verified: web tsc + 181 tests, api tsc + 58 tests, dead-ref sweep clean.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

src/pages/Landing.test.tsx

@@ -14,7 +14,7 @@ function renderLanding() {
 describe('Landing', () => {
   it('renders the workshop headline and date', () => {
     renderLanding()
-    expect(screen.getByRole('heading', { level: 1 })).toHaveTextContent(/on-device agentic systems/i)
+    expect(screen.getByRole('heading', { level: 1 })).toHaveTextContent(/design a domain node/i)
     expect(screen.getByText(/FabLab Torino/i)).toBeInTheDocument()
     expect(screen.getByText(/July 27, 2026/i)).toBeInTheDocument()
   })