fix(web): dashboard quick-actions use SPA soft-nav so the session survives

The wallet keeps `isUnlocked` + the plaintext mnemonic in memory ONLY (never
persisted — see the auth store's partialize), so ANY full-document reload wipes
the session and bounces the user back to onboarding. On mobile this made the
wallet unusable: every full-reload dashboard action effectively logged you out.

- Portfolio dashboard: render the Send / Cross-Chain / Earn / Manage Keys
  quick-action cards as react-router <Link> (client-side soft-nav) instead of
  full-reload <a href>. A tap pushState-navigates and the in-memory unlock +
  mnemonic survive.
- Audit for other session-dropping full-reload links: Callback's "Back to
  wallet" recovery link was a raw <a href="/"> — converted to <Link to="/">.

Verified at 390x844 (iPhone-class): the 4 cards render with no horizontal
overflow (documentElement.scrollWidth == 390); tapping Send soft-navigates to
/send with NO document reload (a page sentinel + the zustand auth store both
survive, isUnlocked stays true); a full-reload navigation (the prior behavior)
wipes the in-memory session — confirming the fix.

Co-authored-by: Hanzo Dev <dev@hanzo.ai>

apps/web/src/screens/auth/Callback.tsx

@@ -10,7 +10,7 @@
  * GPL-3.0-or-later — inherited from the wallet monorepo.
  */
 import { useEffect, useState } from "react"
-import { useNavigate } from "react-router-dom"
+import { Link, useNavigate } from "react-router-dom"
 import { useBrand } from "../../hooks/useBrand"
 import { useSession } from "../../store/session"
 
@@ -43,9 +43,9 @@ export default function Callback(): React.JSX.Element {
         <>
           <h1 style={title}>Sign-in failed</h1>
           <p style={msg}>{error}</p>
-          <a href="/" style={link}>
+          <Link to="/" replace style={link}>
             Back to {brand.walletName || "wallet"}
-          </a>
+          </Link>
         </>
       ) : (
         <>

apps/web/src/screens/portfolio/Portfolio.tsx

@@ -18,7 +18,7 @@
  * placeholders rather than crashing the screen.
  */
 import { lazy, Suspense, useMemo } from "react"
-import { useNavigate } from "react-router-dom"
+import { Link, useNavigate } from "react-router-dom"
 import { mnemonicToAccount, type Address } from "viem/accounts"
 import { Button, Card, Text, XStack, YStack } from "@hanzo/gui"
 import { useAuth } from "../../store/auth"
@@ -67,6 +67,35 @@ function useActiveChainId(): number {
   return 96369
 }
 
+/**
+ * Dashboard quick actions. Each is a react-router <Link> (SPA soft-nav) — NOT
+ * an <a href>. The unlock state + plaintext mnemonic live ONLY in memory (the
+ * auth store never persists them), so a full document reload wipes them and
+ * bounces the user back to onboarding. Soft-nav keeps the session alive.
+ */
+const QUICK_ACTIONS: ReadonlyArray<{ to: string; label: string; icon: string }> = [
+  { to: "/send", label: "Send", icon: "↑" },
+  { to: "/bridge", label: "Cross-Chain", icon: "⇄" },
+  { to: "/stake", label: "Earn", icon: "%" },
+  { to: "/settings/security", label: "Manage Keys", icon: "⚿" },
+]
+
+const quickActionStyle: React.CSSProperties = {
+  display: "flex",
+  flexDirection: "column",
+  alignItems: "center",
+  justifyContent: "center",
+  gap: 6,
+  minWidth: 0,
+  padding: "14px 6px",
+  borderRadius: 12,
+  border: "1px solid var(--surface3, #222)",
+  background: "var(--surface2, #111)",
+  color: "var(--neutral1, #fff)",
+  textDecoration: "none",
+  textAlign: "center",
+}
+
 export default function Portfolio() {
   const navigate = useNavigate()
   const isUnlocked = useAuth((s) => s.isUnlocked)
@@ -119,6 +148,20 @@ export default function Portfolio() {
         </YStack>
       </Card>
 
+      <nav
+        aria-label="Quick actions"
+        style={{ display: "grid", gridTemplateColumns: "repeat(4, 1fr)", gap: 8 }}
+      >
+        {QUICK_ACTIONS.map((a) => (
+          <Link key={a.to} to={a.to} style={quickActionStyle}>
+            <span aria-hidden="true" style={{ fontSize: 20, lineHeight: 1 }}>
+              {a.icon}
+            </span>
+            <span style={{ fontSize: 12, fontWeight: 600 }}>{a.label}</span>
+          </Link>
+        ))}
+      </nav>
+
       <Suspense fallback={null}>
         <ChainSwitcher />
       </Suspense>