fix(proxy): resolve merge conflict in claude adapter — combine smart URL path detection with beta=true

Merge both features from feat/smart-url-path-detection and main:
- Smart URL path detection: skip appending endpoint when base_url already ends with API path
- URL suffix preservation: preserve query/fragment from base_url via split_url_suffix
- v1 dedup: boundary-safe deduplication of /v1/v1
- ?beta=true: auto-append for /v1/messages endpoints (DuckCoding compatibility)

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

src/types.ts

@@ -170,6 +170,7 @@ export interface VisibleApps {
 export interface WebDavSyncStatus {
   lastSyncAt?: number | null;
   lastError?: string | null;
+  lastErrorSource?: string | null;
   lastRemoteEtag?: string | null;
   lastLocalManifestHash?: string | null;
   lastRemoteManifestHash?: string | null;
@@ -178,6 +179,7 @@ export interface WebDavSyncStatus {
 // WebDAV v2 同步配置
 export interface WebDavSyncSettings {
   enabled?: boolean;
+  autoSync?: boolean;
   baseUrl?: string;
   username?: string;
   password?: string;