Migrate remaining Server Actions to ActionResult<T> pattern #102

Summary

PR #100 introduced ActionResult<T> discriminated union type and converted github.ts and user-presets.ts. The remaining Server Action files should be incrementally migrated to this pattern.

Why ActionResult

• Discriminated unions ({ success: true; data: T } | { success: false; error: string }) provide compile-time safety that { data: T | null; error: string | null } cannot. TypeScript narrows the type after checking result.success, so you can safely access result.data or result.error without null checks.
• withAuthResult<T> wraps the try/catch + Sentry reporting in one place, so every server action gets consistent error handling for free. The auth check returns a result object instead of throwing, which means callers never need try/catch for auth failures.

Remaining Files

board.ts (client-consumed functions)

• createBoard — called from CreateBoardForm.tsx (currently throws)
• updateBoardPositions — called from BoardGrid.tsx (currently throws)

shared-project-info.ts → project-info.ts / maintenance-project-info.ts

• upsertProjectInfoCore → wrapper upsertProjectInfo (currently throws)
• updateCommentCore → wrapper updateComment (currently throws)
• updateCommentColorCore → wrapper updateCommentColor (currently throws)
• deleteCommentCore → wrapper deleteComment (currently throws)
• getProjectInfoCore → wrapper getProjectInfo (currently throws on DB error)

repo-cards.ts (type alignment only)

• Already uses { success, error } pattern — just add ActionResult<T> return type annotations

Scope

• DO NOT convert internal/server-component-only functions (e.g., getStatusLists, getBoardData, fetchBoardInitialData) — these can stay throw-based since server components have error boundaries
• DO NOT convert auth.ts — uses redirect(), special flow
• DO NOT convert useActionState functions — they have specific state shapes required by the hook

Source

Established pattern in PR #100 (refactor/error-handling-68), src/lib/actions/types.ts