Add quick-register one-liner for target-host registration

Operator pastes `curl -fsSL $ORCH/register/quick.sh | sudo bash` on the
target host (pre-wipe). The script probes MAC + CPU/RAM/disks/NICs/GPUs,
emits an expected-spec YAML, and POSTs to a new LAN-trusted JSON
endpoint /api/v1/hosts. The register page shows the command prefilled
with the orchestrator URL; the manual form moves into a collapsible
"Register manually" disclosure.

internal/web/static/app.css

@@ -208,3 +208,38 @@ button.danger:hover { background: rgba(229,100,102,.1); }
 .login-card button:hover { background: var(--accent); border-color: var(--accent); }
 
 body.bare main { max-width: none; }
+
+.quick-register {
+  background: var(--bg-elev);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  padding: 16px 18px;
+  margin-bottom: 20px;
+}
+.quick-register h2 { margin: 0 0 8px; font-size: 16px; }
+.quick-register p { margin: 6px 0; font-size: 13px; color: var(--text-dim); }
+.quick-register p b { color: var(--text); }
+.quick-register .muted { color: var(--text-dim); font-weight: 400; }
+.quick-register code { font-family: var(--mono); }
+.quick-register .one-liner {
+  background: #0b0d12;
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  padding: 10px 12px;
+  margin: 8px 0;
+  overflow-x: auto;
+  user-select: all;
+  font-size: 13px;
+  color: var(--text);
+}
+.quick-register .one-liner code { white-space: pre; }
+
+.manual-register { margin-top: 16px; }
+.manual-register summary {
+  cursor: pointer;
+  color: var(--text-dim);
+  font-size: 13px;
+  padding: 6px 0;
+}
+.manual-register summary:hover { color: var(--text); }
+.manual-register[open] summary { margin-bottom: 12px; }