fix(transport): correlate resources/updated notifications

[Priyanshubhartistm]

Summary

This PR fixes a privacy and correctness bug where notifications/resources/updated was being broadcast to all initialized sessions instead of being delivered only to the intended correlated client(s).

What changed

• Implemented a proper correlation path for notifications/resources/updated.
• Switched routing for this notification from fan-out broadcast to targeted delivery.
• Added subscription-aware correlation so delivery is tied to the right recipient(s).
• Kept intentionally broadcast notification behavior unchanged for other notification types.
• Added multi-client regression coverage to verify only intended client(s) receive the update.

Why this fix

The previous behavior could leak sensitive resource updates across sessions, causing privacy and data correctness issues in multi-client environments.

Validation

• Typecheck passed.
• Correlation and server transport focused tests passed.
• Added and passed multi-client targeted-delivery regression test for notifications/resources/updated.

Related issue

Fixes #52

[Priyanshubhartistm]

@ContextVM-org
Could you please review whenever you are free
Thank you