fix(sync): batch inserts + normalize nulls to avoid SQLite param mismatch

- Batch repository inserts with dynamic sizing under SQLite 999-param limit
- Normalize undefined → null to keep multi-row insert shapes consistent
- De-duplicate owned + starred repos by fullName (prefer starred variant)
- Enforce uniqueness via (user_id, full_name) + onConflictDoNothing
- Handle starred name collisions (suffix/prefix) across mirror + metadata
- Add repo-utils helpers + tests; guard Octokit.plugin in tests
- Remove manual unique index from entrypoint; rely on drizzle-kit migrations

src/lib/db/schema.ts

@@ -1,5 +1,5 @@
 import { z } from "zod";
-import { sqliteTable, text, integer, index } from "drizzle-orm/sqlite-core";
+import { sqliteTable, text, integer, index, uniqueIndex } from "drizzle-orm/sqlite-core";
 import { sql } from "drizzle-orm";
 
 // ===== Zod Validation Schemas =====
@@ -28,6 +28,7 @@ export const githubConfigSchema = z.object({
   mirrorStrategy: z.enum(["preserve", "single-org", "flat-user", "mixed"]).default("preserve"),
   defaultOrg: z.string().optional(),
   skipStarredIssues: z.boolean().default(false),
+  starredDuplicateStrategy: z.enum(["suffix", "prefix", "owner-org"]).default("suffix").optional(),
 });
 
 export const giteaConfigSchema = z.object({
@@ -379,6 +380,7 @@ export const repositories = sqliteTable("repositories", {
   index("idx_repositories_organization").on(table.organization),
   index("idx_repositories_is_fork").on(table.isForked),
   index("idx_repositories_is_starred").on(table.isStarred),
+  uniqueIndex("uniq_repositories_user_full_name").on(table.userId, table.fullName),
 ]);
 
 export const mirrorJobs = sqliteTable("mirror_jobs", {
@@ -674,4 +676,4 @@ export type Repository = z.infer<typeof repositorySchema>;
 export type MirrorJob = z.infer<typeof mirrorJobSchema>;
 export type Organization = z.infer<typeof organizationSchema>;
 export type Event = z.infer<typeof eventSchema>;
-export type RateLimit = z.infer<typeof rateLimitSchema>;
+export type RateLimit = z.infer<typeof rateLimitSchema>;