Document analytics API endpoints (OpenAPI/Swagger)

[phertyameen]

Description

Add @nestjs/swagger decorators (@ApiOperation, @ApiResponse, @ApiQuery) to every route in analytics.controller.ts so the module shows up correctly in the app's Swagger docs.

Why this matters

Frontend and integration consumers of the analytics API need discoverable, accurate API documentation instead of reading controller source directly.

Files to touch

• backend/src/analytics/analytics.controller.ts

Acceptance Criteria

• Every analytics route has a Swagger operation summary and response schema
• Query DTOs have @ApiProperty decorators with example values

Notes

This issue is part of the new analytics module effort (tracking, aggregation,
and reporting on player/game activity). Please keep new code inside
backend/src/analytics/ following the same module/controller/service/provider
layout used by existing modules (e.g. progress, streak, quests).

[AnnieIj]

Hi! I'd love to work on this issue.

I plan to document the analytics API endpoints using OpenAPI/Swagger by defining accurate endpoint specifications, request and response schemas, authentication requirements, parameters, and example payloads. I'll ensure the documentation reflects the current implementation, follows the project's API standards, and is easy for developers to understand and use. Could you please assign this issue to me?