feat(observability): phase 3 - direct proxy creation with validation

Add standalone proxy management:
- Multi-step validation pipeline (DNS, TCP, HTTP) with diagnostic hints
- Proxy lifecycle: create/update/delete via NPM API with SSL auto-assign
- Periodic health monitoring (5min) with event log on status transitions
- Unified /api/proxies/all endpoint merging standalone + managed proxies
- Frontend types and API functions for downstream UI phases

web/src/lib/api.ts

@@ -9,11 +9,14 @@ import type {
 	NpmCertificate,
 	Project,
 	ProjectDetail,
+	ProxyView,
 	Registry,
 	RegistryImage,
 	Settings,
 	Stage,
 	StageEnv,
+	StandaloneProxy,
+	ValidationResult,
 	Volume
 } from './types';
 
@@ -365,4 +368,41 @@ export function fetchEventLogStats(): Promise<EventLogStats> {
 	return get<EventLogStats>('/api/events/log/stats');
 }
 
+// ── Proxies ─────────────────────────────────────────────────────────
+
+export function validateProxy(host: string, port: number): Promise<ValidationResult> {
+	return post<ValidationResult>('/api/proxies/validate', { host, port });
+}
+
+export function createProxy(data: {
+	domain: string;
+	destination_url: string;
+	destination_port: number;
+}): Promise<StandaloneProxy> {
+	return post<StandaloneProxy>('/api/proxies', data);
+}
+
+export function listProxies(): Promise<StandaloneProxy[]> {
+	return get<StandaloneProxy[]>('/api/proxies');
+}
+
+export function getProxy(id: string): Promise<StandaloneProxy> {
+	return get<StandaloneProxy>(`/api/proxies/${id}`);
+}
+
+export function updateProxy(
+	id: string,
+	data: { domain: string; destination_url: string; destination_port: number }
+): Promise<StandaloneProxy> {
+	return put<StandaloneProxy>(`/api/proxies/${id}`, data);
+}
+
+export function deleteProxy(id: string): Promise<{ deleted: string }> {
+	return del<{ deleted: string }>(`/api/proxies/${id}`);
+}
+
+export function listAllProxies(): Promise<ProxyView[]> {
+	return get<ProxyView[]>('/api/proxies/all');
+}
+
 export { ApiError };

web/src/lib/types.ts

@@ -198,8 +198,39 @@ export interface StandaloneProxy {
 	destination_port: number;
 	ssl_certificate_id: number;
 	npm_proxy_id: number;
-	health_status: 'unknown' | 'healthy' | 'unhealthy';
+	health_status: ProxyHealthStatus;
 	health_checked_at: string;
 	created_at: string;
 	updated_at: string;
 }
+
+/** Health status for a proxy. */
+export type ProxyHealthStatus = 'unknown' | 'healthy' | 'unhealthy';
+
+/** A single step in the validation pipeline. */
+export interface ValidationStep {
+	name: string;
+	passed: boolean;
+	message?: string;
+	hint?: string;
+}
+
+/** Result of the proxy destination validation pipeline. */
+export interface ValidationResult {
+	valid: boolean;
+	steps: ValidationStep[];
+}
+
+/** Unified view of standalone + deploy-managed proxies (from /api/proxies/all). */
+export interface ProxyView {
+	id: string;
+	domain: string;
+	destination: string;
+	type: 'standalone' | 'managed';
+	project_name?: string;
+	stage_name?: string;
+	health_status: ProxyHealthStatus;
+	ssl_enabled: boolean;
+	npm_proxy_id: number;
+	created_at: string;
+}