feat(warp): register WARP over MASQUE from the WARP modal

xray-core's masque transport reaches Cloudflare WARP with an enrolled
ECDSA P-256 key, the endpoint's public key and the assigned tunnel
addresses, which only a WARP enrollment hands out.

A new regMasque action on /panel/api/xray/warp/:action registers a
separate WARP device and enrolls a secp256r1 key for the masque tunnel
(the API revision and client version the WARP apps enroll MASQUE keys
with). Enrolling replaces a device's WireGuard key, so it never touches
the stored WireGuard registration. It returns the PEM key pair, the
addresses and the endpoint, and the WARP modal turns them into a
warp-masque outbound (HTTP/3, Cloudflare's MASQUE SNI), or refreshes
the one already there.

frontend/src/pages/api-docs/endpoints.ts

@@ -2138,7 +2138,7 @@ export const sections: readonly Section[] = [
             name: 'action',
             in: 'path',
             type: 'string',
-            desc: 'data — return Warp stats. del — delete Warp data. config — return current config. reg — register (sends keys). changeIp — rotate the endpoint. license — set a Warp+ key. interval — set automatic rotation in hours.',
+            desc: 'data — return Warp stats. del — delete Warp data. config — return current config. reg — register (sends keys). regMasque — register a separate device enrolled for MASQUE and return its warp key pair, addresses and endpoint. changeIp — rotate the endpoint. license — set a Warp+ key. interval — set automatic rotation in hours.',
           },
           {
             name: 'privateKey',