Extract duplicated API query helpers into a shared utilities module

[blinkeye-lcm]

Problem

Four API route files each redefine the same low level query helpers with identical bodies:

• positiveInt
• normalizeRepoList
• chunk
• resolveRepoScope

Affected routes:

• src/app/api/pulls/route.ts
• src/app/api/issues/route.ts
• src/app/api/repos/[owner]/[name]/authors/[login]/pulls/route.ts
• src/app/api/repos/[owner]/[name]/authors/[login]/issues/route.ts

The duplication adds noise to every route file, invites drift between copies, and forces multi file edits whenever the repo scope contract or query parsing rules need a tweak.

Proposal

Create src/lib/api-utils.ts and export the four helpers using the most strictly typed signatures already in the codebase:

positiveInt(value: string | null, fallback: number): number
normalizeRepoList(raw: string | null): string[] | null
chunk<T>(items: T[], size: number): T[][]
resolveRepoScope(reqRepos: string[] | null): Promise<string[]>

Replace the inline copies in the four routes above with a single import. Pages such as src/app/miners/page.tsx and src/app/repositories/page.tsx are out of scope and remain untouched.

Acceptance Criteria

• src/lib/api-utils.ts is the single source of truth for the four helpers
• No inline copies remain in the four route files
• Call sites and route behavior stay identical

[github-actions]

Thanks for contributing. Gittensor policy allows at most 2 open issues or pull requests per contributor at a time.

@blinkeye-lcm currently has 3 open issues/PRs, and this is open item #3. Please finish or close one of the older open items before opening another.