Revert "refactor(server): cleanup unused schemas"

This reverts commit ea74b1a.

Author: chenxin-yan

packages/server/convex/http.ts

@@ -139,6 +139,78 @@ export const ZUpsertProgramWithRequirements = z.object({
   ),
 });
 
+export const ZUpsertRequirements = z.array(
+  z.discriminatedUnion("type", [
+    z.object({
+      programId: z.pipe(
+        z.string(),
+        z.transform((val) => val as Id<"programs">),
+      ),
+      isMajor: z.boolean(),
+      description: z.optional(z.string()),
+      type: z.literal("required"),
+      courses: z.array(z.string()),
+    }),
+    z.object({
+      programId: z.pipe(
+        z.string(),
+        z.transform((val) => val as Id<"programs">),
+      ),
+      isMajor: z.boolean(),
+      description: z.optional(z.string()),
+      type: z.literal("alternative"),
+      courses: z.array(z.string()),
+    }),
+    z.object({
+      programId: z.pipe(
+        z.string(),
+        z.transform((val) => val as Id<"programs">),
+      ),
+      isMajor: z.boolean(),
+      description: z.optional(z.string()),
+      type: z.literal("options"),
+      courses: z.array(z.string()),
+      courseLevels: z.array(
+        z.object({
+          program: z.string(),
+          level: z.coerce.number(),
+        }),
+      ),
+      creditsRequired: z.number(),
+    }),
+  ]),
+);
+
+export const ZUpsertPrerequisites = z.array(
+  z.discriminatedUnion("type", [
+    z.object({
+      courseId: z.pipe(
+        z.string(),
+        z.transform((val) => val as Id<"courses">),
+      ),
+      type: z.literal("required"),
+      courses: z.array(z.string()),
+    }),
+    z.object({
+      courseId: z.pipe(
+        z.string(),
+        z.transform((val) => val as Id<"courses">),
+      ),
+      type: z.literal("alternative"),
+      courses: z.array(z.string()),
+    }),
+    z.object({
+      courseId: z.pipe(
+        z.string(),
+        z.transform((val) => val as Id<"courses">),
+      ),
+      type: z.literal("options"),
+      courses: z.array(z.string()),
+      creditsRequired: z.number(),
+    }),
+  ]),
+);
+
 export const ZUpsertCourseOfferings = z.array(
   z.object({
     courseCode: z.string(), // CSCI-UA 102