feat(api): add saved repos tRPC endpoints

- Add getSavedRepos query (protected, feature flag)
- Add updateSavedRepos mutation (protected, feature flag)
- Implement merge logic for sync
- Add Zod validation schemas
- Feature flag: FEATURE_SAVED_REPOS_DB
- Fix z.record() type arguments for Zod compatibility

Author: Lucifer-0612

apps/api/src/routers/user.ts

@@ -1,5 +1,6 @@
 import { router, publicProcedure, protectedProcedure } from "../trpc.js";
 import { userService } from "../services/user.service.js";
+import { savedReposService } from "../services/savedRepos.service.js";
 import { z } from "zod";
 
 export const userRouter = router({
@@ -34,5 +35,81 @@ export const userRouter = router({
         userId,
         input.completedSteps
       );
+    }),
+
+  // get user's saved repos (feature flag: FEATURE_SAVED_REPOS_DB)
+  getSavedRepos: protectedProcedure.query(async ({ ctx }: any) => {
+    if (process.env.FEATURE_SAVED_REPOS_DB !== "true") {
+      return [];
+    }
+    const userId = ctx.user.id;
+    return await savedReposService.getSavedRepos(ctx.db.prisma, userId);
   }),
+
+  // update user's saved repos with merge logic (feature flag: FEATURE_SAVED_REPOS_DB)
+  updateSavedRepos: protectedProcedure
+    .input(
+      z.object({
+        action: z.enum(["add", "remove", "replace"]),
+        repos: z.array(
+          z.object({
+            id: z.string(),
+            name: z.string(),
+            url: z.string(),
+            language: z.string().optional(),
+            popularity: z.enum(["low", "medium", "high"]).optional(),
+            competitionScore: z.number().optional(),
+            savedAt: z.string(),
+            meta: z.record(z.string(), z.any()).optional(),
+          })
+        ),
+        localRepos: z
+          .array(
+            z.object({
+              id: z.string(),
+              name: z.string(),
+              url: z.string(),
+              language: z.string().optional(),
+              popularity: z.enum(["low", "medium", "high"]).optional(),
+              competitionScore: z.number().optional(),
+              savedAt: z.string(),
+              meta: z.record(z.string(), z.any()).optional(),
+            })
+          )
+          .optional(),
+      })
+    )
+    .mutation(async ({ ctx, input }: any) => {
+      if (process.env.FEATURE_SAVED_REPOS_DB !== "true") {
+        throw new Error("Saved repos sync is not enabled");
+      }
+
+      const userId = ctx.user.id;
+
+      // If localRepos provided, merge with server repos
+      if (input.localRepos && input.action === "replace") {
+        const serverRepos = await savedReposService.getSavedRepos(
+          ctx.db.prisma,
+          userId
+        );
+        const merged = savedReposService.mergeSavedRepos(
+          input.localRepos,
+          serverRepos
+        );
+        return await savedReposService.updateSavedRepos(
+          ctx.db.prisma,
+          userId,
+          "replace",
+          merged
+        );
+      }
+
+      // Otherwise, perform the requested action
+      return await savedReposService.updateSavedRepos(
+        ctx.db.prisma,
+        userId,
+        input.action,
+        input.repos
+      );
+    }),
 });