feat(memory-core): expose hybrid search component scores

Expose raw `vectorScore` and `textScore` alongside the combined hybrid memory search `score`.

- Preserve vector/text component scores from `mergeHybridResults` output.
- Add optional component-score fields to both memory host SDK type surfaces.
- Extend hybrid merge tests for vector-only, text-only, and overlapping result cases.
- Document that component scores remain raw retrieval diagnostics while temporal decay/MMR only adjust or reorder the combined ranking `score`.

Closes #68166.

Maintainer verification:
- `pnpm test extensions/memory-core/src/memory/hybrid.test.ts`
- `pnpm check:changed`
- Fresh GitHub checks passed.

Co-authored-by: Alex Fries <alex@engramlabs.io>

extensions/memory-core/src/memory/hybrid.test.ts

@@ -60,7 +60,11 @@ describe("memory hybrid helpers", () => {
     const a = merged.find((r) => r.path === "memory/a.md");
     const b = merged.find((r) => r.path === "memory/b.md");
     expect(a?.score).toBeCloseTo(0.7 * 0.9);
+    expect(a?.vectorScore).toBeCloseTo(0.9);
+    expect(a?.textScore).toBe(0);
     expect(b?.score).toBeCloseTo(0.3 * 1.0);
+    expect(b?.vectorScore).toBe(0);
+    expect(b?.textScore).toBeCloseTo(1.0);
   });
 
   it("mergeHybridResults prefers keyword snippet when ids overlap", async () => {
@@ -94,5 +98,7 @@ describe("memory hybrid helpers", () => {
     expect(merged).toHaveLength(1);
     expect(merged[0]?.snippet).toBe("kw-a");
     expect(merged[0]?.score).toBeCloseTo(0.5 * 0.2 + 0.5 * 1.0);
+    expect(merged[0]?.vectorScore).toBeCloseTo(0.2);
+    expect(merged[0]?.textScore).toBeCloseTo(1.0);
   });
 });

extensions/memory-core/src/memory/hybrid.ts

@@ -72,6 +72,8 @@ export async function mergeHybridResults(params: {
     startLine: number;
     endLine: number;
     score: number;
+    vectorScore: number;
+    textScore: number;
     snippet: string;
     source: HybridSource;
   }>
@@ -131,11 +133,15 @@ export async function mergeHybridResults(params: {
       startLine: entry.startLine,
       endLine: entry.endLine,
       score,
+      vectorScore: entry.vectorScore,
+      textScore: entry.textScore,
       snippet: entry.snippet,
       source: entry.source,
     };
   });
 
+  // Keep component scores as raw retrieval diagnostics; temporal decay and MMR
+  // only adjust or reorder the combined ranking score.
   const temporalDecayConfig = { ...DEFAULT_TEMPORAL_DECAY_CONFIG, ...params.temporalDecay };
   const decayed = await applyTemporalDecayToHybridResults({
     results: merged,

packages/memory-host-sdk/src/host/types.ts

@@ -5,6 +5,8 @@ export type MemorySearchResult = {
   startLine: number;
   endLine: number;
   score: number;
+  vectorScore?: number;
+  textScore?: number;
   snippet: string;
   source: MemorySource;
   citation?: string;

src/memory-host-sdk/host/types.ts

@@ -5,6 +5,8 @@ export type MemorySearchResult = {
   startLine: number;
   endLine: number;
   score: number;
+  vectorScore?: number;
+  textScore?: number;
   snippet: string;
   source: MemorySource;
   citation?: string;