Add network diagnostic tool for domain connectivity troubleshooting

DNS lookup (DoH via Cloudflare/Google), Korean ISP block detection
(KT/LG/SK via TCP DNS), HTTP/HTTPS check, and TCP port test — all
run in parallel with per-check timeouts. Integrated as diagnose_domain
tool in troubleshoot-agent with updated patterns for network keywords.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/types.ts

@@ -16,11 +16,14 @@ export interface Env {
   DEPOSIT_BANK_HOLDER?: string;
   // API URLs
   OPENAI_API_BASE?: string;
-  D2_RENDER_URL?: string;
   NAMECHEAP_API_URL?: string;
   WHOIS_API_URL?: string;
   CLOUD_ORCHESTRATOR_URL?: string;
   CLOUD_ORCHESTRATOR?: Fetcher;
+  // Kroki
+  KROKI_URL?: string;
+  // Queues
+  WORK_QUEUE?: Queue;
   // KV Namespaces
   RATE_LIMIT_KV: KVNamespace;
   SESSION_KV: KVNamespace;
@@ -401,10 +404,6 @@ export interface CheckServiceArgs {
   service_id?: number;
 }
 
-export interface RenderD2Args {
-  source: string;
-  format?: 'svg' | 'png';
-}
 
 export interface AdminArgs {
   action: 'block_user' | 'unblock_user' | 'set_role' | 'broadcast' | 'confirm_deposit' | 'reject_deposit' | 'list_pending';
@@ -421,6 +420,60 @@ export interface ApproveActionArgs {
   reason?: string;
 }
 
+// ============================================
+// Network Diagnostic Types
+// ============================================
+
+export interface DnsRecord {
+  type: string;
+  value: string;
+  ttl?: number;
+}
+
+export interface DnsResolverResult {
+  resolver: string;
+  ip: string;
+  records: DnsRecord[];
+  responseTimeMs: number;
+  error?: string;
+}
+
+export interface IspDnsBlockResult {
+  isp: string;
+  serverIp: string;
+  resolvedIps: string[];
+  blocked: boolean;
+  blockReason?: string;
+  responseTimeMs: number;
+  error?: string;
+}
+
+export interface HttpCheckResult {
+  url: string;
+  statusCode?: number;
+  responseTimeMs: number;
+  redirectUrl?: string;
+  error?: string;
+}
+
+export interface TcpCheckResult {
+  host: string;
+  port: number;
+  connected: boolean;
+  responseTimeMs: number;
+  error?: string;
+}
+
+export interface NetworkDiagnosticReport {
+  domain: string;
+  timestamp: string;
+  dns: DnsResolverResult[];
+  ispBlocking: IspDnsBlockResult[];
+  http: HttpCheckResult[];
+  tcp: TcpCheckResult[];
+  summary: string[];
+}
+
 // ============================================
 // Inline Keyboard Data
 // ============================================
@@ -448,21 +501,6 @@ export type KeyboardCallbackData =
   | ActionApprovalKeyboardData
   | EscalationKeyboardData;
 
-// ============================================
-// D2 Rendering
-// ============================================
-
-export interface D2RenderRequest {
-  source: string;
-  format: 'svg' | 'png';
-}
-
-export interface D2RenderResponse {
-  success: boolean;
-  image?: ArrayBuffer;
-  error?: string;
-}
-
 // ============================================
 // Request Context
 // ============================================