feat: add community enhancements — password reset, audit logs, multi-source backup

Three community-requested features:

1. CLI password reset: `backupx reset-password --username admin --password xxx`
   Docker users can run via `docker exec`. No full app init needed.

2. Audit logging: async fire-and-forget audit trail for all key operations
   (login, CRUD on tasks/targets/records, settings changes).
   New UI page at /audit with category filter and pagination.

3. Multi-source path backup: file backup tasks now support multiple source
   directories packed into a single tar archive. Backward compatible with
   existing single sourcePath field.

web/src/services/audit.ts

@@ -0,0 +1,7 @@
+import { http } from './http'
+import type { AuditLogListResult } from '../types/audit'
+
+export async function listAuditLogs(params: { category?: string; limit?: number; offset?: number }) {
+  const response = await http.get<{ code: string; message: string; data: AuditLogListResult }>('/audit-logs', { params })
+  return response.data.data
+}

web/src/services/database.ts

@@ -0,0 +1,18 @@
+import { http, type ApiEnvelope, unwrapApiEnvelope } from './http'
+
+export interface DatabaseDiscoverPayload {
+  type: 'mysql' | 'postgresql'
+  host: string
+  port: number
+  user: string
+  password: string
+}
+
+interface DatabaseDiscoverResult {
+  databases: string[]
+}
+
+export async function discoverDatabases(payload: DatabaseDiscoverPayload): Promise<string[]> {
+  const response = await http.post<ApiEnvelope<DatabaseDiscoverResult>>('/database/discover', payload, { timeout: 10000 })
+  return unwrapApiEnvelope(response.data).databases ?? []
+}

web/src/services/storage-targets.ts

@@ -74,6 +74,11 @@ export interface StorageTargetUsage {
   totalSize: number
 }
 
+export async function toggleStorageTargetStar(id: number) {
+  const response = await http.put<ApiEnvelope<StorageTargetSummary>>(`/storage-targets/${id}/star`)
+  return unwrap(response.data)
+}
+
 export async function getStorageTargetUsage(id: number) {
   const response = await http.get<ApiEnvelope<StorageTargetUsage>>(`/storage-targets/${id}/usage`)
   return unwrap(response.data)