[Multi-Tenancy] Migrate OpenCTI connector to tenant-scoped

[RomuDeuxfois]

Proposed changes

Testing Instructions

1. Step-by-step how to test
2. Environment or config notes

Related issues

• Closes #ISSUE-NUMBER

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality
• For bug fix -> I implemented a test that covers the bug

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc...

[github-actions]

🤖 Copilot Agent Review Scope

Metric	Value
Files changed	37
PR size	🔴 large

Agents triggered

• 🔒 Security Reviewer — RBAC, auth, data exposure
• ⚡ Performance Reviewer — N+1, fetch strategy, pagination
• 🏠 Multi-Tenancy Reviewer — tenant isolation, cross-tenant leaks
• 🧪 Test Specialist — missing test coverage detected

💡 To invoke an agent manually, comment on this PR:
/review security · /review perf · /review tenancy · /review tests · /review all

⚠️ Large PR Warning

This PR has >500 lines added. Consider splitting into smaller, focused PRs for better review quality.