feat(observability): phase 1 - schema, models & event log backend

Add database foundation for observability features:
- event_log table with severity/source filtering and pagination
- standalone_proxies table for user-created reverse proxies
- stale_threshold_days setting (default 7 days)
- Auto-persist warn/error events from event bus to database
- SSE broadcast of persistent events for real-time UI updates
- Frontend types and API functions for downstream UI phases

web/src/lib/api.ts

@@ -2,6 +2,8 @@ import type {
 	ApiEnvelope,
 	Deploy,
 	DeployLog,
+	EventLogEntry,
+	EventLogStats,
 	InspectResult,
 	Instance,
 	NpmCertificate,
@@ -338,4 +340,29 @@ export function deleteVolume(
 	return del<{ deleted: string }>(`/api/projects/${projectId}/volumes/${volId}`);
 }
 
+// ── Event Log ───────────────────────────────────────────────────────
+
+export function fetchEventLog(params?: {
+	severity?: string;
+	source?: string;
+	since?: string;
+	until?: string;
+	limit?: number;
+	offset?: number;
+}): Promise<EventLogEntry[]> {
+	const query = new URLSearchParams();
+	if (params?.severity) query.set('severity', params.severity);
+	if (params?.source) query.set('source', params.source);
+	if (params?.since) query.set('since', params.since);
+	if (params?.until) query.set('until', params.until);
+	if (params?.limit) query.set('limit', String(params.limit));
+	if (params?.offset) query.set('offset', String(params.offset));
+	const qs = query.toString();
+	return get<EventLogEntry[]>(`/api/events/log${qs ? `?${qs}` : ''}`);
+}
+
+export function fetchEventLogStats(): Promise<EventLogStats> {
+	return get<EventLogStats>('/api/events/log/stats');
+}
+
 export { ApiError };