feat(memory): add experimental qmd search backend

src/memory/index.ts

@@ -8,6 +8,8 @@ export { VectorStore, cosineSimilarity, contentHash } from './vector-store.js';
 export type { VectorSearchResult, EmbeddingRow } from './vector-store.js';
 export { HybridSearch } from './hybrid-search.js';
 export type { HybridSearchResult } from './hybrid-search.js';
+export { QmdSearch } from './qmd-search.js';
+export type { QmdSearchOptions } from './qmd-search.js';
 export * from './categories.js';
 export { buildAdaptiveMemoryContext, buildRecentMemoryContext } from './adaptive.js';
 export type { AdaptiveMemoryConfig } from './adaptive.js';