feat(plan): resolveGrid for batch cell resolution

src/__tests__/plan.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect, beforeAll, afterAll, beforeEach } from "vitest";
 import prisma from "../config/database";
-import { resolveCell } from "../services/plan.service";
+import { resolveCell, resolveGrid } from "../services/plan.service";
 
 // ---------------------------------------------------------------------------
 // Test fixtures
@@ -119,3 +119,54 @@ describe("plan.service.resolveCell", () => {
     expect(result).toBeNull();
   });
 });
+
+// ---------------------------------------------------------------------------
+// resolveGrid
+// ---------------------------------------------------------------------------
+
+describe("plan.service.resolveGrid", () => {
+  it("returns a 2D map keyed by userId then date", async () => {
+    await prisma.work_plan_entries.create({
+      data: {
+        user_id: adminUserId,
+        date_from: new Date("2099-06-01"),
+        date_to: new Date("2099-06-03"),
+        category: "work",
+        note: `${N}A`,
+        created_by: adminUserId,
+      },
+    });
+    const cells = await resolveGrid([adminUserId], "2099-06-01", "2099-06-05");
+    expect(cells[adminUserId]["2099-06-01"]?.note).toBe(`${N}A`);
+    expect(cells[adminUserId]["2099-06-02"]?.note).toBe(`${N}A`);
+    expect(cells[adminUserId]["2099-06-03"]?.note).toBe(`${N}A`);
+    expect(cells[adminUserId]["2099-06-04"]).toBeNull();
+    expect(cells[adminUserId]["2099-06-05"]).toBeNull();
+  });
+
+  it("applies override on a covered day", async () => {
+    await prisma.work_plan_entries.create({
+      data: {
+        user_id: adminUserId,
+        date_from: new Date("2099-06-01"),
+        date_to: new Date("2099-06-03"),
+        category: "work",
+        note: `${N}A`,
+        created_by: adminUserId,
+      },
+    });
+    await prisma.work_plan_overrides.create({
+      data: {
+        user_id: adminUserId,
+        shift_date: new Date("2099-06-02"),
+        category: "leave",
+        note: `${N}B`,
+        created_by: adminUserId,
+      },
+    });
+    const cells = await resolveGrid([adminUserId], "2099-06-01", "2099-06-03");
+    expect(cells[adminUserId]["2099-06-01"]?.note).toBe(`${N}A`);
+    expect(cells[adminUserId]["2099-06-02"]?.note).toBe(`${N}B`);
+    expect(cells[adminUserId]["2099-06-03"]?.note).toBe(`${N}A`);
+  });
+});