feat(tls,reality): port xray TLS/REALITY fields, cert-hash helpers, fallback UX

TLS: add verifyPeerCertByName (vcn) to inbound settings + emit in both share-link generators (frontend + Go sub) and outbound parser; the allowInsecure replacement xray removed after 2026-06-01. Add server-side curvePreferences, masterKeyLog, echSockopt (passthrough + form) at tlsSettings top-level so they survive the panel-only settings strip.

REALITY: add limitFallbackUpload/Download (afterBytes/bytesPerSec/burstBytesPerSec) with per-field tooltips, plus masterKeyLog. Verified field names/semantics against pinned xray v1.260327.1 (bytesPerSec=0 disables).

Hosts: fix verify_peer_cert_by_name column bool->string (xray expects comma-separated names) with an idempotent, history-gate-free migration (SQLite typeof blank; Postgres ALTER once); emit vcn for hosts/external proxies.

Server: add getCertHash (local cert DER SHA-256) and getRemoteCertHash (xray tls ping) endpoints + api-docs; wire pinned-cert field buttons. Drop the meaningless random-hash button.

Xray UI: metrics endpoint (listen/tag) config in Basics; import/export for routing rules and outbounds.

Fallbacks card: compact empty state, header-aligned actions, responsive labeled grid rows.

i18n: add all new keys to every locale; drop unused generateRandomPin.

frontend/src/test/host-link.test.ts

@@ -13,6 +13,7 @@ describe('hostToExternalProxyEntry', () => {
     alpn: ['h2'] as ('h2' | 'h3' | 'http/1.1')[],
     fingerprint: 'chrome' as const,
     pinnedPeerCertSha256: ['AAAA'],
+    verifyPeerCertByName: 'verify.example.com',
     echConfigList: 'ECH',
     overrideSniFromAddress: false,
     keepSniBlank: false,
@@ -28,6 +29,7 @@ describe('hostToExternalProxyEntry', () => {
     expect(ep.alpn).toEqual(['h2']);
     expect(ep.fingerprint).toBe('chrome');
     expect(ep.pinnedPeerCertSha256).toEqual(['AAAA']);
+    expect(ep.verifyPeerCertByName).toBe('verify.example.com');
     expect(ep.echConfigList).toBe('ECH');
   });