Add Batch Operations API

[Mkalbani]

Description

Allow batch operations for efficiency (e.g., delete multiple solutions).

Use Cases

• Moderator needs to delete 10 spam solutions
• Admin wants to archive 50 old problems
• User wants to bookmark multiple solutions

Acceptance Criteria

• POST /api/v1/solutions/batch with actions
• Support actions: delete, bookmark, update-status
• Return results for each item (success/failure)
• Limit to 50 items per batch
• Require appropriate permissions for each item

Example Request

{
  "action": "delete",
  "solutionIds": [1, 2, 3, 5, 8]
}

Example Response

{
  "results": [
    { "id": 1, "success": true },
    { "id": 2, "success": true },
    { "id": 3, "success": false, "error": "Not authorized" },
    { "id": 5, "success": true },
    { "id": 8, "success": false, "error": "Not found" }
  ]
}

ETA: 4 hours

[Lynndabel]

Hello, I have carefully reviewed this issue description and acceptance criteria and will like to work on this please. ETA is 3hours. Please assign me this, thanks

[OmniZlatoon]

Hi maintainer sir, I'm called Junior Brown , a full-stack and smart contract engineer building on Stellar. I specialize in designing and shipping scalable, secure systems end-to-end, from Soroban smart contracts to production-ready backend infrastructure and user-facing applications.

I’ve worked on complex architectures involving automated agents, cross-chain logic, and data indexing, focusing on reliability, performance, and clean standards. My approach is very product-driven: I don’t just build contracts, I build complete systems that solve real user problems and can scale in production.

I’m especially interested in infrastructure, security, and automation creating tools and frameworks that make it easier for other developers to build safely and efficiently on Stellar.