feat(db): lab_drafts, lab_draws, biomarkers tables

Refs PAI-91.

server/test/db-labs.test.ts

@@ -0,0 +1,21 @@
+import { describe, expect, test } from "bun:test";
+import { mkdtempSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { openDb } from "../src/db";
+import { biomarkers, labDraws } from "../src/db/schema";
+
+describe("labs schema", () => {
+  test("draw + biomarker round-trip", async () => {
+    const db = openDb(mkdtempSync(join(tmpdir(), "helios-")));
+    await db.insert(labDraws).values({ id: "d1", collectedAt: "2026-01-15", labName: "Acme Lab", draftId: null, createdAt: 1 });
+    await db.insert(biomarkers).values({
+      drawId: "d1", panel: "lipids", name: "LDL Cholesterol", marker: "ldl", analyteKey: "ldl",
+      value: "3.1", valueNum: 3.1, unit: "mmol/L", referenceRange: "< 3.4", flagged: 0,
+      valueCanonical: 3.1, canonicalUnit: "mmol/L",
+    });
+    const rows = await db.select().from(biomarkers);
+    expect(rows).toHaveLength(1);
+    expect(rows[0].marker).toBe("ldl");
+  });
+});