feat: add regression ingestion and runs APIs

[Mo2Hefny]

• Regression Ingestion APIs: Added endpoints to handle data ingestion tailored for the generated regression framework.
• DagsHub S3 Artifacts Service: Implemented a new artifact service integrated with DagsHub via an S3-compatible bucket layer.
• API Key Authentication: Introduced API_KEY validation support to secure application requests and authenticate users within the framework.
• Run Events & Completion Tracking: Added support for tracking run lifecycle events and capturing final completion artifacts.
• Test Coverage: Added comprehensive unit and integration tests to ensure stability across all new services.

[github-actions]

🧪 Test & Coverage Report

Metric	Result
Status	✅ Passed
Tests	✅ 221 passed / 221 total
Suites	28 passed / 28 total

Coverage

Category	Coverage	Covered / Total
🟡 Statements	71.43%	1538 / 2153
🔴 Branches	45.72%	444 / 971
🟡 Functions	60.2%	177 / 294
🟡 Lines	72.83%	1469 / 2017

Updated for commit 75df6b4