Add agentic retrieval response fields to RetrievalQueryResponse

[EricNGOntos]

Summary

The Knowhere retrieval API has been updated (knowhere#57) with a slimmed response contract and a new per-request useAgentic toggle. The Node SDK needs to sync its types accordingly.

Changes Required

1. New Request Parameter: useAgentic

Add useAgentic?: boolean to client.retrieval.query():

const response = await client.retrieval.query({
  namespace: 'support-center',
  query: 'How do I reset Bluetooth pairing?',
  useAgentic: true,   // force agentic mode
  // useAgentic: false  // force legacy 3-channel RRF
  // omit useAgentic    // use server default
});

console.log(response.answerText);  // LLM-generated answer
console.log(response.referencedChunks);  // cited evidence

Value	Behavior
true	Force agentic retrieval (LLM navigation + answer synthesis)
false	Force legacy retrieval (3-channel RRF only)
undefined / omitted	Use server default (RETRIEVAL_AGENTIC_ENABLED env var)

2. New Response Fields

Add two optional fields to the retrieval response interface:

Field	Type	Description
answerText	string | null	LLM-generated natural-language answer (agentic mode only)
referencedChunks	Array<object> | null	Cited evidence chunks with assetUrl (agentic mode only)

3. New Request Parameter: dataType

Add dataType?: number (1-6) for chunk type filtering:

Value	Filter
1	All types (default)
2	Text only
3	Image only
4	Table only
5	Text + Image
6	Text + Table

4. Removed (do NOT add)

• enableDecomposition — removed from API, was deprecated
• plan, steps, finalStrategyUsed, walletSnapshot, plannerSnapshot, evidenceText — removed from response, internal debug fields

Final API Contract (as of knowhere#57)

Request:

interface RetrievalQueryRequest {
  namespace?: string;
  query: string;
  topK?: number;                    // default 10
  useAgentic?: boolean;             // NEW
  dataType?: number;                // 1-6, default 1
  excludeDocumentIds?: string[];
  excludeSections?: ExcludeSection[];
  signalPaths?: string[];
  filterMode?: 'delete' | 'keep';
  channels?: ('path' | 'content' | 'term')[];
  channelWeights?: Record<string, number>;
  rerank?: boolean;
  threshold?: number;
  internalRecallK?: number;
}

Response:

interface RetrievalQueryResponse {
  namespace: string;
  query: string;
  routerUsed: string;
  answerText: string | null;            // NEW - agentic LLM answer
  referencedChunks: Array<object>;      // NEW - cited evidence
  results: Array<RetrievalResult>;      // legacy chunk results
}

Acceptance Criteria

• useAgentic parameter supported in client.retrieval.query()
• dataType parameter supported
• Response interface includes answerText and referencedChunks
• At least one example shows useAgentic: true with response.answerText
• Existing tests pass (all new fields are optional)