feat: multi-wallet architecture with localStorage state, EIP-712 verification, cross-tab WS leadership

- wallets.js: WalletManager state management with chain validation
- verifier.js: WalletVerifier EIP-712 signing via window.ethereum
- stream.js: WalletStreamManager with BroadcastChannel leader election, backoff + jitter
- AGENTS.md: updated with coding guidelines

AGENTS.md

@@ -0,0 +1,58 @@
+# cbBTC Treasury Dashboard
+
+**What it is:** A single-page HTML dashboard tracking cbBTC acquisition across wallets. No build step, no JS framework, no tests — just one `index.html` served by nginx.
+
+## How to run
+
+```bash
+docker build -t cbBTC-dashboard . && docker run -p 8080:80 cbBTC-dashboard
+```
+
+Or just open `index.html` in a browser (without the `/api/` proxy, only the Kraken BTC price chart will work).
+
+## File layout
+
+| File | Purpose |
+|---|---|
+| `index.html` | Everything. Frontend, embedded chart data, inline JS logic. Edit here. |
+| `Dockerfile` | 4 lines. Copies `index.html` and `default.conf` into `nginx:alpine`. |
+| `default.conf` | Reverse proxy: `/api/` → `http://192.168.1.102:8000/api/`. |
+| `aave_portfolio.md` / `wallet_portfolio.md` | Reference data dumps. NOT consumed by the app. |
+
+## Key facts for editing `index.html`
+
+- **Data is embedded as JS constants** near the top of the `<script>` block:
+  - `walletCumulData` — time-series of cumulative BTC per wallet
+  - `dailySatsData` — rolling sats/day with price info
+  - `walletsMetadata` — wallet id → address, name, color, chain
+  - `walletCosts` / `walletBuys` — cost basis per wallet
+- **API endpoints** (proxied through nginx):
+  - `GET /api/v1/prices/{symbol}/history?range=N` — price history
+  - `GET /api/v1/portfolio/{address}/base/aave` — Aave portfolio snapshots
+- **BTC price** fetched directly from Kraken: `https://api.kraken.com/0/public/OHLC?pair=XBTUSD&interval=1440`
+- **Polling:** `setInterval` every 30s with a 60s throttle on the Aave endpoint
+- **Tracked wallet:** `0x0c1a4a060e119f981412e323104d1c134d413dba` ("penguin", Base)
+- **Token decimals:** cbBTC=8, WETH=18, USDC=6
+
+## Gotchas
+
+- `apiBase = window.location.origin` — the dashboard relies on nginx proxy to reach the backend at `192.168.1.102:8000`. Running without Docker/proxy means the Aave table and price charts fail silently.
+- No linting, no type-checking, no CI. Validate changes by opening the HTML in a browser.
+- Adding chart data? Update the embedded arrays (`walletCumulData`, etc.) — they are plain JS arrays of `[timestampMs, value]` pairs.
+
+## Coding Guidelines
+
+You are an expert senior Web3 frontend engineer specializing in high-scale performance and stateless cryptographic security.
+
+We are building the client-side code for an anonymous multi-wallet tracker. The application handles up to 100k concurrent connections, so code efficiency, memory management, and avoiding redundant network overhead are paramount.
+
+1. **Modern TypeScript/JavaScript** — clean, modular, and well-commented.
+2. **No bloated third-party UI frameworks** — stick to vanilla methods or standard state hooks.
+3. **Production-ready error handling** — bulletproof handling for wallet rejections and network drops.
+
+## After every `index.html` edit
+
+Always rebuild and restart the Docker container so changes take effect:
+```bash
+docker build -t cbbtc-dashboard . && docker stop dione-dashboard && docker rm dione-dashboard && docker run -d --name dione-dashboard -p 8080:80 cbbtc-dashboard
+```