[Sprint] Categories: Refactor handlers to use ObjectId and return Result<T>

[mpaulosky]

Problem

Category handlers (Get, List, Create, Update, Delete) mirror the same problems as Issues: runtime ObjectId parsing in handlers, no Result propagation to endpoints.

Depends On

Depends on: Foundation issue (standardize ObjectId in Shared commands/queries)

Files to Modify

• src/Api/Handlers/Categories/GetCategoryHandler.cs — return Task<Result>
• src/Api/Handlers/Categories/ListCategoriesHandler.cs — return Task<Result<IReadOnlyList>>
• src/Api/Handlers/Categories/CreateCategoryHandler.cs — return Task<Result>
• src/Api/Handlers/Categories/UpdateCategoryHandler.cs — return Task<Result>
• src/Api/Handlers/Categories/DeleteCategoryHandler.cs — return Task<Result>
• src/Api/Handlers/Categories/CategoryEndpoints.cs — map Result → HTTP responses

Acceptance Criteria

• All 5 Category handlers return Task<Result>
• No ObjectId.TryParse() in handler bodies
• CategoryEndpoints maps Result → proper HTTP status codes
• Solution builds with zero errors and zero warnings

[github-actions]

🏗️ Squad Triage — Aragorn (Lead)

Issue: #83 — [Sprint] Categories: Refactor handlers to use ObjectId and return Result
Assigned to: Legolas (Frontend Dev)
Reason: Issue relates to frontend/UI work

@copilot evaluation: No strong capability match — routed to squad member.

Team roster:

• Aragorn (Lead) → label: squad:aragorn
• Legolas (Frontend Dev) → label: squad:legolas
• Sam (Backend Dev) → label: squad:sam
• Gimli (Tester) → label: squad:gimli
• Boromir (DevOps) → label: squad:boromir
• Frodo (Tech Writer) → label: squad:frodo
• Gandalf (Security Officer) → label: squad:gandalf
• Ralph (Work Monitor) → label: squad:ralph
• @copilot (🤖 Coding Agent) → label: squad:@copilot
• @copilot (Coding Agent) → label: squad:copilot

To reassign, remove the current squad:* label and add the correct one.

[github-actions]

📋 Assigned to Sam (Backend Dev)

Issue: #83 — [Sprint] Categories: Refactor handlers to use ObjectId and return Result

Sam will pick this up in the next Copilot session.

For Copilot coding agent: If enabled, this issue will be worked automatically.
Otherwise, start a Copilot session and say:
Sam, work on issue #83

[mpaulosky]

Resolved in PR #92 (merged to main).