feat(desktop): Contacts + Settings→Devices + expanded Profile + QR + keybinds (v2.2.0-rc1)

Completes the desktop feature surface ahead of the v2.2.0 tag. Only
auto-update + packaging remain.

Settings — now two-paned (nav on the left, pages on the right):
  * NodePage — URL ping-on-commit + API token field.
  * IdentityPage — pub key / X25519 pub, Export (safe-save dialog) /
    Import (open dialog + wipe + replace) / Delete identity.
  * DevicesPage — full multi-device UI: list every active device with
    a THIS DEVICE badge; Unlink button on every other row submits
    UNLINK_DEVICE + optimistic local remove; Link new device modal
    takes {code, device key, name}, submits LINK_DEVICE, then ships
    the handshake envelope (master Ed25519 priv encrypted for the
    new X25519) — same protocol as mobile's primary-device modal.
  * AboutPage — version, platform, Gitea links.
  * store.settingsPage discriminated union keeps selection across
    section switches.

Contacts section (now real):
  * ContactsList — alphabetical, filter-as-you-type; each row shows
    avatar letter + name + short address.
  * ContactsDetail — profile card (username/alias/pub) + Open chat /
    View posts / Copy address actions + stats grid
    (Balance, Devices, Encryption, Added) + Identity card with
    DC address, username, published X25519, device_count.
  * store.selectedContact persists across navigation.

Profile section (expanded):
  * ProfileList — big avatar + pub key + contacts count.
  * ProfileDetail — balance hero, quick actions (My posts →
    feed author wall, Manage devices → Settings→Devices, Copy
    address), Identity card, inline Linked devices list with a
    THIS DEVICE badge matching the Settings page.

Receive modal — canvas QR via `qrcode` (new dep, ~5 KB gzipped),
white-on-transparent so it sits inside the same black modal chrome.

Global keybinds (useGlobalKeybinds hook mounted in Shell):
  * Ctrl/Cmd+W — close the current conversation (drops activeChat,
    keeps section). Does NOT close the window.
  * Ctrl/Cmd+K — jump to Contacts.
  * Ctrl/Cmd+, — Settings.
  Each guards against being in a text field so typing `k,` in a
  composer / search doesn't hijack.

docs/ROADMAP.md — rc1 row flipped to done; v2.2.0 narrows to
auto-update + packaging + optional attachments in Compose.

desktop/src/sections/contacts/ContactsDetail.tsx

@@ -0,0 +1,200 @@
+// Right-pane for Contacts — profile card for the selected contact.
+// Shows identity, balance, device count, linked action buttons:
+// Open chat (switch to Messages section), Transfer, View posts (switch
+// to Feed author wall), Block (local only for now).
+
+import React, { useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getIdentity, fetchDevices, getBalance } from '@/lib/api';
+import { shortAddr } from '@/lib/crypto';
+import type { IdentityInfo } from '@/lib/api';
+
+function formatT(ut: number): string {
+  return (ut / 1_000_000).toLocaleString(undefined, { maximumFractionDigits: 3 });
+}
+
+export function ContactsDetail(): React.ReactElement {
+  const sel        = useStore(s => s.selectedContact);
+  const contact    = useStore(s => s.contacts.find(c => c.address === sel));
+  const setSection = useStore(s => s.setSection);
+  const setActive  = useStore(s => s.setActiveChat);
+  const setFeedTab = useStore(s => s.setFeedTab);
+
+  const [identity,    setIdentity]    = useState<IdentityInfo | null>(null);
+  const [balance,     setBalance]     = useState<number | null>(null);
+  const [deviceCount, setDeviceCount] = useState<number | null>(null);
+
+  useEffect(() => {
+    if (!sel) return;
+    let cancelled = false;
+    (async () => {
+      const [id, bal, devs] = await Promise.all([
+        getIdentity(sel),
+        getBalance(sel),
+        fetchDevices(sel),
+      ]);
+      if (cancelled) return;
+      setIdentity(id);
+      setBalance(bal);
+      setDeviceCount(devs.length);
+    })();
+    return () => { cancelled = true; };
+  }, [sel]);
+
+  if (!sel || !contact) {
+    return (
+      <div style={{
+        height: '100%', display: 'flex',
+        alignItems: 'center', justifyContent: 'center',
+        color: '#6a6a6a', fontSize: 13, padding: 40, textAlign: 'center',
+      }}>
+        Pick a contact on the left to view their profile.
+      </div>
+    );
+  }
+
+  const displayName = contact.username
+    ? `@${contact.username}`
+    : (identity?.nickname ? `@${identity.nickname}` : (contact.alias ?? shortAddr(contact.address, 8)));
+
+  const openChat = () => {
+    setActive(contact.address);
+    setSection('messages');
+  };
+  const viewPosts = () => {
+    setFeedTab({ kind: 'author', pub: contact.address });
+    setSection('feed');
+  };
+  const copy = (s: string) => navigator.clipboard.writeText(s).catch(() => {});
+
+  return (
+    <div style={{
+      height: '100%', overflowY: 'auto',
+      padding: '22px 26px', background: '#000',
+    }}>
+      {/* Header card */}
+      <div style={{ display: 'flex', alignItems: 'center', gap: 14 }}>
+        <div style={{
+          width: 64, height: 64, borderRadius: 32,
+          background: '#1a1a1a', color: '#d0d0d0',
+          display: 'flex', alignItems: 'center', justifyContent: 'center',
+          fontSize: 28, fontWeight: 700,
+        }}>{displayName.replace(/^@/, '').charAt(0).toUpperCase()}</div>
+        <div style={{ flex: 1, minWidth: 0 }}>
+          <div style={{ color: '#fff', fontSize: 22, fontWeight: 800 }}>
+            {displayName}
+          </div>
+          <div className="selectable" style={{
+            color: '#8b8b8b', fontSize: 12, fontFamily: 'monospace',
+            marginTop: 4, wordBreak: 'break-all',
+          }}>{contact.address}</div>
+        </div>
+      </div>
+
+      {/* Actions */}
+      <div style={{ display: 'flex', gap: 10, marginTop: 16, flexWrap: 'wrap' }}>
+        <Btn primary onClick={openChat}>Open chat</Btn>
+        <Btn onClick={viewPosts}>View posts</Btn>
+        <Btn onClick={() => copy(contact.address)}>Copy address</Btn>
+      </div>
+
+      {/* Stats grid */}
+      <div style={{
+        marginTop: 22, display: 'grid',
+        gridTemplateColumns: 'repeat(auto-fit, minmax(180px, 1fr))', gap: 10,
+      }}>
+        <Stat label="Balance"     value={balance === null ? '…' : `${formatT(balance)} T`} />
+        <Stat label="Devices"     value={deviceCount === null ? '…' : String(deviceCount)} />
+        <Stat label="Encryption"  value={contact.x25519Pub ? 'E2E (NaCl)' : 'no key'} />
+        <Stat label="Added"       value={new Date(contact.addedAt).toLocaleDateString()} />
+      </div>
+
+      {/* Identity details */}
+      {identity && (
+        <div style={{
+          marginTop: 22, padding: 14, borderRadius: 12,
+          background: '#0a0a0a', border: '1px solid #1f1f1f',
+        }}>
+          <div style={{
+            color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+            letterSpacing: 1, textTransform: 'uppercase', marginBottom: 8,
+          }}>Identity</div>
+          <Row k="DC address" v={identity.address} copyable onCopy={() => copy(identity.address)} />
+          {identity.nickname && <Row k="Username" v={`@${identity.nickname}`} />}
+          {identity.x25519_pub && (
+            <Row
+              k="Published X25519"
+              v={shortAddr(identity.x25519_pub, 8)}
+              copyable
+              onCopy={() => copy(identity.x25519_pub)}
+            />
+          )}
+          {typeof identity.device_count === 'number' && (
+            <Row k="Device count" v={String(identity.device_count)} />
+          )}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function Btn({ children, onClick, primary }: {
+  children: React.ReactNode; onClick: () => void; primary?: boolean;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        padding: '9px 16px', borderRadius: 999,
+        background: primary ? '#1d9bf0' : 'transparent',
+        border: primary ? 'none' : '1px solid #1f1f1f',
+        color: '#fff', fontSize: 13, fontWeight: 700, cursor: 'pointer',
+      }}
+    >{children}</button>
+  );
+}
+
+function Stat({ label, value }: { label: string; value: string }) {
+  return (
+    <div style={{
+      padding: 12, borderRadius: 12,
+      background: '#0a0a0a', border: '1px solid #1f1f1f',
+    }}>
+      <div style={{
+        color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+        letterSpacing: 1, textTransform: 'uppercase',
+      }}>{label}</div>
+      <div style={{ color: '#fff', fontSize: 15, fontWeight: 700, marginTop: 4 }}>
+        {value}
+      </div>
+    </div>
+  );
+}
+
+function Row({
+  k, v, copyable, onCopy,
+}: { k: string; v: string; copyable?: boolean; onCopy?: () => void }) {
+  return (
+    <div style={{
+      display: 'flex', padding: '6px 0',
+      borderBottom: '1px solid #141414',
+      alignItems: 'center', gap: 10,
+    }}>
+      <div style={{ color: '#8b8b8b', fontSize: 12, flex: '0 0 140px' }}>{k}</div>
+      <div className="selectable" style={{
+        color: '#fff', fontSize: 13, fontFamily: 'monospace',
+        flex: 1, wordBreak: 'break-all',
+      }}>{v}</div>
+      {copyable && (
+        <button
+          onClick={onCopy}
+          style={{
+            background: 'transparent', border: 'none',
+            color: '#1d9bf0', fontSize: 11, fontWeight: 600,
+            cursor: 'pointer',
+          }}
+        >copy</button>
+      )}
+    </div>
+  );
+}