Feat/queues and handlers

[Muizzyranking]

Summary

Provide a brief overview of the changes in this PR.

Type of Change

• [x ] New Feature
• Bug Fix
• Refactor
• Chore (dependencies, documentation, etc.)
• Test Addition/Update

Key Changes

Summary

This PR implements the core job processing engine and scheduling logic. It introduces a
modular queue system (supporting Priority and Timing Wheel algorithms), a flexible job
handling framework, and the essential domain services for DAG management, Dead Letter
Queues (DLQ), and alerting.

Type of Change

• New Feature
• Refactor (Modularizing queue and handler interfaces)

Key Changes

• Queue System: Implemented a base QueueInterface with two concrete implementations:
• HeapQ: For priority-based scheduling.
• TimingWheel: Optimized for delayed job execution.
• Job Handlers: Created handlers for Webhook, Email, and Log processing, including a utility for dynamic payload parsing.
• Domain Services:
  • JobService: Central interface for job lifecycle management.
  • DAGService: Logic for managing job dependencies and execution order.
  • DLQService: Management for failed jobs/dead letter queues.
  • SettingService: Centralized application configuration management.
• Alerting: Implemented an AlertService with HTML email templates for DLQ
  threshold notifications.
• Schemas: Comprehensive Pydantic models for Job definitions and states.

Database Migrations

• This PR includes database migrations (alembic/versions/).
• Migrations have been tested locally.

Testing Strategy

• Manual verification of queue logic (HeapQ and Timing Wheel).
• Payload parsing utilities verified against various job schemas.
• Email template rendering tested locally.

Checklist

• Code follows the project's style guidelines.
• uv.lock and pyproject.toml are updated.
• Documentation (in docs/) has been updated if necessary.
• I have verified the changes in a local environment.- [ ] List major architectural or logic changes.
• Mention new database models or schema updates.
• Describe any new API endpoints or services.

Database Migrations

• This PR includes database migrations (alembic/versions/).
• Migrations have been tested locally.

Testing Strategy

• Unit tests added/updated.
• Integration tests added/updated.
• Manual testing performed.

Checklist

• Code follows the project's style guidelines.
• uv.lock and pyproject.toml are updated.
• Documentation (in docs/) has been updated if necessary.
• I have verified the changes in a local environment.

Screenshots / Console Logs

(Optional: Add any relevant visual evidence of the change)