Wallet discovery: detect Phantom (window.phantom.ethereum) + legacy providers[]

Phantom exposes its EVM provider at window.phantom.ethereum and does not always
fire EIP-6963, so the picker never saw it. probeInjected() now folds in Phantom
and any window.ethereum.providers[] entries (deduped by identity + name) for
both pick() and list(). Phantom added to the mobile in-app-browser hint and the
dashboard no-wallet message.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

private/join-now.html

@@ -27,7 +27,7 @@
       <a id="mmDeep" class="btn btn-secondary" style="width:100%;margin-bottom:8px" href="#">🦊 Open in MetaMask</a>
       <a id="twDeep" class="btn btn-secondary" style="width:100%;margin-bottom:10px" href="#">🛡️ Open in Trust Wallet</a>
       <div style="border-top:1px solid var(--line);padding-top:10px">
-        <div style="font-weight:700;font-size:13px;margin-bottom:4px">📲 Using SafePal, Coinbase Wallet, Rabby, or another app?</div>
+        <div style="font-weight:700;font-size:13px;margin-bottom:4px">📲 Using SafePal, Phantom, Coinbase Wallet, Rabby, or another app?</div>
         <p class="micro" style="margin:0">Every wallet app has its own built-in browser — that's how it connects. Open <strong>your wallet app</strong> → find the <strong>Browser</strong> or <strong>DApp</strong> tab (SafePal: the compass/🧭 "DApps" tab at the bottom) → type <strong>rmcircle.team/join/<span id="wbId">…</span></strong> and open it there. Your wallet appears automatically, ready to connect — no matter which wallet you use.</p>
       </div>
       <p class="micro" style="margin:8px 0 0">⚠️ <strong>Trust Wallet bouncing you back here?</strong> Trust's built-in browser is switched off by default. <a href="https://link.trustwallet.com/browser_enable" rel="noopener">Tap here to switch it on</a> (or in Trust: Settings → Preferences → DApp Browser → enable), then tap "Open in Trust Wallet" again.</p>