feat(control-panel): web admin UI for the zero-touch tunnel

Loopback Fastify auth-broker + esbuild SPA. Operator password login (constant-time,
signed HttpOnly session cookie, per-forwarded-IP rate-limit) → session-gated proxy
that mints a fresh 60s manage capability token per call to the control-plane admin
API: list hosts, mint pairing codes (with QR + pair command), revoke hosts. Security
headers + CSP, CP_URL pinned loopback (anti-SSRF), hostId dot-segment guard. 55 tests
pass; security-reviewed. Deployed behind nginx panel.terminal.yaojia.wang.

control-panel/test/compare.test.ts

@@ -0,0 +1,31 @@
+import { describe, it, expect } from 'vitest'
+import { constantTimeEqual, constantTimeEqualBytes } from '../src/security/compare.js'
+
+describe('constantTimeEqual', () => {
+  it('returns true for identical strings', () => {
+    expect(constantTimeEqual('correct-horse', 'correct-horse')).toBe(true)
+  })
+
+  it('returns false for different strings', () => {
+    expect(constantTimeEqual('correct-horse', 'battery-staple')).toBe(false)
+  })
+
+  it('returns false for different-length strings (no length oracle)', () => {
+    expect(constantTimeEqual('abc', 'abcdef')).toBe(false)
+  })
+
+  it('returns false when either side is empty or undefined', () => {
+    expect(constantTimeEqual('', 'x')).toBe(false)
+    expect(constantTimeEqual('x', '')).toBe(false)
+    expect(constantTimeEqual(undefined, 'x')).toBe(false)
+    expect(constantTimeEqual('x', undefined)).toBe(false)
+  })
+})
+
+describe('constantTimeEqualBytes', () => {
+  it('true for equal buffers, false for differing or mismatched length', () => {
+    expect(constantTimeEqualBytes(Buffer.from('aa'), Buffer.from('aa'))).toBe(true)
+    expect(constantTimeEqualBytes(Buffer.from('aa'), Buffer.from('ab'))).toBe(false)
+    expect(constantTimeEqualBytes(Buffer.from('aa'), Buffer.from('aaa'))).toBe(false)
+  })
+})