feat(memory): add Nowledge Mem provider integration

Add a new memory provider that delegates to a local Nowledge Mem instance
for memory storage, retrieval, and knowledge graph building.

Key design decisions:
- User messages tagged as [DisplayName], bot messages as [我]
- Per-message display name parsed from YAML front-matter headers
- Let Nowledge Mem handle entity extraction and graph building
- 6-way hybrid search (semantic + full-text + entity + community + label + graph)

New files:
- internal/memory/adapters/nowledgemem/client.go (REST API client)
- internal/memory/adapters/nowledgemem/nowledgemem.go (Provider impl)
- docs/nowledge-mem.md (design document with research and decisions)

Modified: types.go, service.go, serve.go (provider registration),
frontend (add-memory-provider.vue, types.gen.ts, i18n locales)

packages/sdk/src/types.gen.ts

@@ -271,7 +271,7 @@ export type AdaptersProviderStatusResponse = {
     provider_type?: string;
 };
 
-export type AdaptersProviderType = 'builtin' | 'mem0' | 'openviking';
+export type AdaptersProviderType = 'builtin' | 'mem0' | 'openviking' | 'nowledgemem';
 
 export type AdaptersProviderUpdateRequest = {
     config?: {