fix(web): name the Arduino Uno Q (4 GB) as the workshop node

Front-end still told the old UNO R4 WiFi story (Cortex-M4 / Renesas
RA4M1 / ~6 MB binary / UART→ESP32-S3 / browser-direct Web Serial).
The actual workshop node is the dual-brain Uno Q: ZeroClaw runs on
the quad-A53 Linux side, hosts a local Qwen model, and flashes the
on-board STM32U585 MCU it drives.

- Landing: hero, hardware spec tile, kit pickup, Stack cards, prereqs
- Lecture: Movement 3 (ZeroClaw) rewritten to the Uno Q architecture
- serial.ts + callers: device identity strings uno-r4-wifi -> uno-q
  (Web Serial transport mechanism unchanged)
- README stack line
- tests updated to match

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

src/pages/Landing.test.tsx

@@ -23,7 +23,7 @@ describe('Landing', () => {
     renderLanding()
     expect(screen.getByText(/5h 30m/i)).toBeInTheDocument()
     expect(screen.getByText(/15 teams/i)).toBeInTheDocument()
-    expect(screen.getAllByText(/Arduino UNO R4/i).length).toBeGreaterThan(0)
+    expect(screen.getAllByText(/Arduino Uno Q/i).length).toBeGreaterThan(0)
   })
 
   it('has a primary CTA linking to /workshop', () => {