feat(mental-health): make the screener score rows server-owned COMPUTED measurements

Each completed PHQ-9 / GAD-7 administration already projects its total
onto a PHQ9_SCORE / GAD7_SCORE measurement row (unit score, linked via
externalId assessment:<id>). Those rows were attributed MANUAL — a
client-writable source. The projection is a server-derived value, so it
now writes source COMPUTED, the same server-owned source RECOVERY_SCORE
uses: no client write surface can attribute COMPUTED, so a forged score
trend point cannot enter through the measurement POST. Migration 0225
re-attributes the existing assessment-linked projection rows; a score a
user typed into the generic measurement form keeps MANUAL. OpenAPI
description updated and the spec regenerated.

src/app/api/mental-health/assessments/__tests__/route.test.ts

@@ -183,12 +183,22 @@ describe("POST /api/mental-health/assessments", () => {
     expect(createArg.data.item9Flagged).toBe(false);
 
     // Derived projection: one PHQ9_SCORE/GAD7_SCORE Measurement per assessment.
+    // Server-owned: the row carries the COMPUTED source (the RECOVERY_SCORE
+    // precedent) — a client can never attribute COMPUTED on a write surface,
+    // so the trend cannot be forged through the measurement POST.
     const measArg = vi.mocked(prisma.measurement.create).mock.calls[0][0] as {
-      data: { type: string; value: number; unit: string; externalId: string };
+      data: {
+        type: string;
+        value: number;
+        unit: string;
+        source: string;
+        externalId: string;
+      };
     };
     expect(measArg.data.type).toBe("GAD7_SCORE");
     expect(measArg.data.value).toBe(6);
     expect(measArg.data.unit).toBe("score");
+    expect(measArg.data.source).toBe("COMPUTED");
     expect(measArg.data.externalId).toBe("assessment:mha_2");
   });
 

src/app/api/mental-health/assessments/route.ts

@@ -308,9 +308,11 @@ async function postAssessment(request: NextRequest): Promise<Response> {
   // chart/rollup infra reads the trend without ever touching item content. The
   // externalId anchors the trend point to this administration; duplicate trend
   // points are structurally impossible because a replayed externalId returns
-  // the existing assessment above before reaching this create. `MeasurementSource`
-  // carries no WEB/IOS member (a screener is questionnaire input, not a device
-  // sample), so the row stays MANUAL — the WEB/IOS provenance + client
+  // the existing assessment above before reaching this create. The row is
+  // `COMPUTED` — a server-derived projection of the encrypted answers, exactly
+  // like RECOVERY_SCORE: clients cannot attribute the COMPUTED source on any
+  // write surface, so a forged PHQ9_SCORE / GAD7_SCORE trend point can never
+  // enter through the measurement POST. The WEB/IOS provenance + client
   // externalId live on the assessment this row links to.
   await prisma.measurement.create({
     data: {
@@ -318,7 +320,7 @@ async function postAssessment(request: NextRequest): Promise<Response> {
       type: INSTRUMENT_MEASUREMENT_TYPE[id] as MeasurementType,
       value: total,
       unit: "score",
-      source: "MANUAL" as MeasurementSource,
+      source: "COMPUTED" as MeasurementSource,
       measuredAt: when,
       notes: null,
       externalId: `assessment:${assessment.id}`,