Add observable request correlation across HTTP, queue, DB, and WebSocket layers

[grantfox-oss]

Establish a single trace/correlation model so operators can follow one request or background action across the NestJS app, queue, and realtime services.

• Affected files: app/backend/src/app.module.ts, app/backend/src/main.ts, app/backend/src/common/middleware/correlation-id.middleware.ts, app/backend/src/metrics/metrics.middleware.ts, app/backend/src/metrics/metrics.interceptor.ts, app/backend/src/metrics/metrics.service.ts, app/backend/src/chat/chat.module.ts, app/backend/src/job-queue/job-queue.module.ts, app/backend/README.md
• Acceptance criteria:
  • HTTP and background jobs emit a consistent correlation identifier and structured timing metadata.
  • Metrics and logs can be correlated across multiple services without ad hoc parsing.
  • Operational docs explain how to trace a single request from inbound HTTP to downstream processing.

[Dijjy7]

i will like to work on this

[grantfox-oss]

🦊 GrantFox — @Dijjy7 has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #563)
2. Your PR will be reviewed by the BlockDash-Studios maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Third Campaign campaign!

@Dijjy7's PR #565 was approved and merged by @MaryammAli.

🏆 @Dijjy7: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (236 total points). Track your full progress on GrantFox.

👏 Great work, @Dijjy7! Keep contributing to BlockDash-Studios.