Hub invite/profile emails should preserve the hub URL path

[Odzen]

Replaces old issues #975 and #985.

Problem

When a partner creates a profile from a hub invite link, follow-up emails should keep the user in the hub-specific flow. Today the profile creation flow sends generic verification/profile links, so users can be routed back to the root MENTEE app instead of the hub path.

Required behavior

• If a partner profile is created from /{hubUrl}/invite/{inviteKey}, emails sent during and after profile creation should use hub-aware URLs.
• Verification and follow-up buttons should return to the correct hub context where applicable.
• Generic MENTEE profile creation should continue using generic URLs.

Acceptance criteria

• Hub invite partner creates profile successfully.
• The verification email button/link includes the correct hub URL path or a hub-aware return path.
• The profile-completed notification/link does not route the hub user to the root app unless that is explicitly intended.
• SendGrid dynamic-template data receives the correct link value for hub-created profiles.
• Add a backend or integration-level test for hub vs non-hub link generation if feasible.